Show pageOld revisionsBacklinksExport to PDFODT exportBack to top This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. ====== PMIP publications for AR6 ====== Document generated on **Wed Aug 28 11:00:41 2019** Number of submitted references: **177** Notes: * References are not sorted, and listed in the order they were submitted to the //PMIP publications for the AR6-WG1 questionnaire// * There may be some duplicates (same ref submitted by different people) ===== Chapter 1: Framing, context, methods ===== Number of selected references: **11** * Shi, H., B. Wang, E. R. Cook, J. Liu, and F. Liu, 2018: Asian summer precipitation over the past 544 years reconstructed by merging tree rings and historical documentary records. J. Clim., 31, 7845-7861, https://doi.org/10.1175/JCLI-D-18-0003.1 * The paper presents a new gridded Asian summer precipitation reconstruction (8.75°S-55.25°N, 61.25°-143.25°E) since AD 1470, and discussed the long-term variability modes of the past summer precipitation over Asian land. * Wu, C. J.; Usoskin, I. G.; Krivova, N. et al., 2018: Solar activity over nine millennia: A consistent multi-proxy reconstruction, Astronomy & Astrophysics, Volume 615, id.A93, 13 pp., https://doi.org/10.1051/0004-6361/201731892 * This paper describes the state-of-the-art method and the results of the first multi-isotope composite, which is used to reconstruct the solar activity over the Holocene. * C.-J. Wu, N. A. Krivova et al., 2018, Solar total and spectral irradiance reconstruction over the last 9000 years, A&A, Forthcoming article, https://doi.org/10.1051/0004-6361/201832956 * This paper describes the methods and the state-of-the-art results of solar irradiance reconstruction over the last 9000 years using a physics-based model. The reconstructed irradiance is recommended to serve as solar forcing in climate models. * Otto-Bliesner, B.L. et al., 2017: The PMIP4 contribution to CMIP6 - Part 2: Two interglacials, Scientific objectives and experimental design of the PMIP4-CMIP6 Holocene and Last Interglacial simulations. Geoscientific Model Development, 10, 3979-4003, https://doi.org/10.5194/gmd-10-3979-2017 * This paper describes the protocols for the mid-Holocene (6 ka) and Last Interglacial (127 ka) Tier 1 simulations, as well as numerous Tier 2 simulations to assess the sensitivities to prescribed vegetation, ice sheets, freshwater fluxes, and alternative states of orbital forcing. For the first time, the LIG is included for CMIP6 and PMIP4, allowing a multi-model assessment of this important period for testing our knowledge of climate-ice sheet interactions in warm climates. * Kadow, C., S. Illing, I. Kröner, U. Ulbrich and U. Cubasch, 2017: Decadal climate predictions improved by ocean ensemble dispersion filtering. J. Adv. Model. Earth Syst. 9, doi 10.1002/2016M5000787 * recent mode development and its performance improvements * Zanchettin, D., Khodri, M., Timmreck, C., Toohey, M., Schmidt, A., Gerber, E. P., Hegerl, G., Robock, A., Pausata, F. S. R., Ball, W. T., Bauer, S. E., Bekki, S., Dhomse, S. S., LeGrande, A. N., Mann, G. W., Marshall, L., Mills, M., Marchand, M., Niemeier, U., Poulain, V., Rozanov, E., Rubino, A., Stenke, A., Tsigaridis, K., and Tummon, F.: The Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP): experimental design and forcing input data for CMIP6, Geosci. Model Dev., 9, 2701-2719, doi:10.5194/gmd-9-2701-2016, 2016, 10.5194/gmd-9-2701-2016, 2016 * This paper presents the experimental design of the "Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP), which includes idealized experiments focused on the short-term atmospheric as well as long-term coupled response to volcanic forcing. The core idea of VolMIP is to constrain radiative forcing among the participating models to focus on the climatic response, hence reference forcing dataare provided in terms of optical aerosol properties for a series of reference eruptions. * Zanchettin, D., O. Bothe, H. F. Graf, S. J. Lorenz, J. Luterbacher, C. Timmreck, and J. H. Jungclaus (2013) Background conditions influence the decadal climate response to strong volcanic eruptions. J. Geophys. Res. Atm., 118(10): 4090-4106, doi:10.1002/jgrd.50229, 10.1002/jgrd.50229 * This study illustrates how the decadal climate response to strong volcanic eruptions depends on the background climate state at the time of the eruption and on the presence and magnitude of additional external forcings acting at the same time. It demonstrates that background climate conditions are not merely a source of additive noise for post-eruption decadal climate variability but actively influence the mechanisms involved in the post-eruption decadal evolution. * Fernández-Donado, L. et al, 2013. Large-scale temperature response to external forcing in simulations and reconstructions of the last millennium. Climate of the Past, 9 (1), pp. 393-421., https://doi.org/10.5194/cp-9-393-2013 * This paper represents an extensive review of the state-of-the-art modelling and reconstructions effort for the last millennium (LM) previous to the coordinated approach within the CMIP5-PMIP3 community, as the basis of knowledge achieved prior the agreement of LM radiative forcings. Additionally, this work provides a quantitative framework to analyse the consistency between reconstructions and simulations in their response to external forcings and the respective role of the internal variability. * Pavón-Carrasco, F.J. et al., 2018. Multi-centennial fluctuations of radionuclide production rates are modulated by the Earth's magnetic field. Scientific reports, 8(1), p.9820, https://doi.org/10.1038/s41598-018-28115-4 * A revision of the standard accepted assumptions to reconstruct the solar activity during the Holocene is presented in this work. It is shown that not only the solar magnetic field but also the geomagnetic field has a relevant role for the timescales of interest. The latter suggests the need of reviewing how past solar forcing estimations are obtained, with relevant implications for the solar-climate relation as well as for the present and future generation of paleo simulations. * Harrison, S. P., Bartlein, P. J., Izumi, K., Li, G., Annan, J., Hargreaves, J., et al. (2015). Evaluation of CMIP5 palaeo-simulations to improve climate projections. Nature Climate Change, 5(8), 735-743. , http://doi.org/10.1038/nclimate2649 * Past climate changes provide a unique opportunity for out-of-sample evaluation of model performance. Palaeo-evaluation has shown that the large-scale changes seen in twenty-first-century projections, including enhanced land-sea temperature contrast, latitudinal amplification, changes in temperature seasonality and scaling of precipitation with temperature, are likely to be realistic. * Schmidt, G. A., Annan, J. D., Bartlein, P. J., Cook, B. I., Guilyardi, E., Hargreaves, J. C., et al. (2014). Using palaeo-climate comparisons to constrain future projections in CMIP5. Climate of the Past, 10(1), 221-250. , http://doi.org/10.5194/cp-10-221-2014 * Using palaeo-climate comparisons to constrain future projections! ===== Chapter 2: Changing state of the climate system ===== Number of selected references: **87** * PAGES2k-PMIP3 group: Bothe O, M. Evans, L. Fernández Donado, E. Garcia Bustamante, J. Gergis, F. J. Gonzalez-Rouco, H. Goosse , G. Hegerl, A. Hind, J. Jungclaus, D. Kaufman, F. Lehner, N. McKay, A. Moberg, C. C. Raible, A. Schurer, F. Shi, J. Smerdon, L. von Gunten, S. Wagner, E. Warren, M. Widmann, P. Yiou, E. Zorita, 2015. Continental-scale temperature variability in PMIP3 simulations and PAGES 2k regional temperature reconstructions over the past millennium. Climate of the Past, 11, 1673-1699, 2015 www.clim-past.net/11/1673/2015/ , https://doi.org/10.5194/cp-11-1673-2015 * The paper presents a thorough comparison between simulation and model results at the continental scale over the past millennium * Klein F., H. Goosse, D. Verschuren, N. Graham, 2016. Comparison of simulated and reconstructed variations in East African hydroclimate over the last millennium. Climate of the Past Clim. Past, 12, 1499-1518 , https://doi.org/10.5194/cp-12-1499-2016 * The paper shows the large role of natural variability in past precipitation changes in East Africa and discuss the role of Indian ocean SST. * Shi, H., B. Wang, E. R. Cook, J. Liu, and F. Liu, 2018: Asian summer precipitation over the past 544 years reconstructed by merging tree rings and historical documentary records. J. Clim., 31, 7845-7861, https://doi.org/10.1175/JCLI-D-18-0003.1 * The paper presents a new gridded Asian summer precipitation reconstruction (8.75°S-55.25°N, 61.25°-143.25°E) since AD 1470, and discussed the long-term variability modes of the past summer precipitation over Asian land. * Shi, H., and B. Wang, 2018: How does the Asian summer precipitation-ENSO relationship change over the past 544 years? Clim. Dyn., https://doi.org/10.1007/s00382-018-4392-z * The paper presents the secular changes (centennial) of the Asian summer precipitation-ENSO relationship since AD 1470 and the possible causes. It also discussed the major modes of variability of the Asian summer rainfall on the interannual timescale. * Fasullo, J.T., R. Tomas, S. Stevenson, B. Otto-Bliesner, E. Brady, E. Wahl, 2017: The amplifying influence of increased ocean stratification on a future year without a summer, Nature Communications, 8, 1236. doi:10.1038/s41467-017-01302-z, https://doi.org/10.1038/s41467-017-01302-z * CESM simulations of both the 1815 Tambora eruption and a hypothetical analogous future eruption are compared, the latter occurring in 2085 assuming a business-as-usual climate scenario. The 1815 eruption drove strong responses in both the ocean and cryosphere that were fundamental to driving the Year-Without-A-Summer. Through modulation of ocean stratification and near-surface winds, global warming contributes to an amplified surface climate response in CESM. * Stevenson, S, J. Overpeck, J. T. Fasullo, S. Coats, L. Parsons, B. Otto-Bliesner, T. R. Ault, G. Loope, J. Cole, 2018: Climate Variability, Volcanic Forcing, and Last Millennium Climate Extremes, Journal of Climate, 31, 4309-4327., n/a * The Community Earth System Model (CESM) Last Millennium Ensemble to examine statistical associations between regional mega-events (megadroughts and megapluvials), coupled climate modes, forcing from major volcanic eruptions. * Hood, L., S. Schimanke, Th. Spangehl, S. Bal, and U. Cubasch, 2013: The surface climate response to 11-yr solar forcing during northern winter: observational analyses and comparisons with GCM simulations. J. Climate, 26, 7489-7506., doi: http://dx.doi.org/10.1175/JCLI-D-12-00843.1 * analysis of the natural climate response to the 11-year solar cycle * 97. Langematz, U., A. Kubin, C. Brühl, A. J. G. Baumgaertner, U. Cubasch, and Th. Spangehl, 2013: Solar Effects on Chemistry and Climate Including Ocean Interactions. Chapter 29, Climate and Weather of the Sun-Earth System (CAWSES): Highlights from a Priority Program, Ed. F. J. Lübken, p 541-571. Springer, , DOI: 10.1007/978-94-007-4348-9_29. * Solar effects on natural variability * Polanski, S., B. Fallah, D. J. Befort, S. Prasad and U. Cubasch, 2014: Regional moisture change over India during the past Millenium: A comparison of multi-proxy reconstructions and climate model simulations. Global and Planetary Change, 122, 176-185, , dx.doi.org.10.1016/J.gloplacha.2014.08.016 * regional moisture variability during the past millennium over India * Bürger, G. and U. Cubasch, 2015: The detectability of climate engineering. J. Geophys. Res. Atmos., 120, , doi:10.1002/2015JD023954 * application of radiative forcing climate engineering * Fallah, B., U. Cubasch, K. Prömmel, S. Sodoudi, 2015: A numerical model study on the behaviour of Asian summer monsoon and AMOC due to orographic forcing of Tibetan Plateau. Clim. Dyn, DOI 10.1007/s00382-015-2914-5. * link between AMOC and Asian summer monsoon * Otto-Bliesner, B.L. et al., 2017: The PMIP4 contribution to CMIP6 - Part 2: Two interglacials, Scientific objectives and experimental design of the PMIP4-CMIP6 Holocene and Last Interglacial simulations. Geoscientific Model Development, 10, 3979-4003, doi:10.5194/cp-12-1645-2016 * regional temperature evolution over Europe during the Holocene * Babian, S., H. W. Rust, J. Grieger, K. Prömmel and U. Cubasch, 2016: Representation of the Antarctic Oscillation and related precipitation patterns in the MPI Earth System Model, Met. Zeitschrift, , DOI 10.1127/metz/2016/0661 * Antarctic oscillation variability and modeled precipitation pattern * Bal, S., S. Schimanke, T. Spangehl and U. Cubasch, 2017: Variable influence on the equatorial troposphere associated with SSW using ERA-interim. J. Earth. Sys. Sci., 126:19, DOI10.1007/sl2040-017-0802-6 * Natural variability of SSW and tropical troposphere * Babian, S., J. Grieger and U. Cubasch, 2018: A new index for the wintertime southern hemisphere split jet. Atmos. Chem. Phys., 18, 6749-6760, doi.org/10.5194/acp-18-6749-2018 * improved description of southern hemisphere variability * Wei Shang, Xuejuan Ren, Bo Huang, Ulrich Cubasch and Xiu-qun Yang, 2018: Subseasonal intensity variations of the South Asian high in relationship to diabatic heating: observation and CMIP5 models. Clim. Dyn, doi.org/10.1007/s00382-018-4266-4 * Linking regional sub seasonal variability with diabetic heat sources * Bo Huang, Ulrich Cubasch and Yan Li, 2018: East-Asian Summer Monsoon Representation in Re-Analysis Datasets. Atmosphere, 9, 235, , doi:10.3390/atmos9060235 * Evaluation of the description of the regional variability in different re-analysis Dara sets * Bal, S., S. Schimanke, T. Spangehl and U. Cubasch, 2018: Enhanced mean meridional circulation during the evolution of split type sudden stratospheric warming in observations and model simulations. J. Earth Syst. Sci. 127:68, doi 10.1007/s12040-018-0972-x * variability of SSWs and connection to meridional circulation * Ohgaito, R., Abe-Ouchi, A., O'ishi, R., Takemura, T., Ito, A., Hajima, T., Watanabe, S., and Kawamiya, M.: Effect of high dust amount on surface temperature during the Last Glacial Maximum: a modelling study using MIROC-ESM, Clim. Past, 14, 1565-1581, https://doi.org/10.5194/cp-14-1565-2018, 2018, https://doi.org/10.5194/cp-14-1565-2018 * Effect of aerosols on climate is major uncertainty for future projection.This paper discusses how the glaciogenic dust can affect the LGMclimate. A possibility of less cooling by high dust load surroundingof Antarctica is suggested. * Chevalier, M., Brewer, S., Chase, B.M., 2017. Qualitative assessment of PMIP3 rainfall simulations across the eastern African monsoon domains during the mid-Holocene and the Last Glacial Maximum. Quat. Sci. Rev. 156, 107-120., 10.1016/j.quascirev.2016.11.028 * The paper evaluates the simulated rainfall patterns in southeastern Africa during the mid-Holocene and the LGM. * Zanchettin, D., Khodri, M., Timmreck, C., Toohey, M., Schmidt, A., Gerber, E. P., Hegerl, G., Robock, A., Pausata, F. S. R., Ball, W. T., Bauer, S. E., Bekki, S., Dhomse, S. S., LeGrande, A. N., Mann, G. W., Marshall, L., Mills, M., Marchand, M., Niemeier, U., Poulain, V., Rozanov, E., Rubino, A., Stenke, A., Tsigaridis, K., and Tummon, F.: The Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP): experimental design and forcing input data for CMIP6, Geosci. Model Dev., 9, 2701-2719, doi:10.5194/gmd-9-2701-2016, 2016, 10.5194/gmd-9-2701-2016, 2016 * This paper presents the experimental design of the "Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP), which includes idealized experiments focused on the short-term atmospheric as well as long-term coupled response to volcanic forcing. The core idea of VolMIP is to constrain radiative forcing among the participating models to focus on the climatic response, hence reference forcing dataare provided in terms of optical aerosol properties for a series of reference eruptions. * Zanchettin, D., O. Bothe, H. F. Graf, S. J. Lorenz, J. Luterbacher, C. Timmreck, and J. H. Jungclaus (2013) Background conditions influence the decadal climate response to strong volcanic eruptions. J. Geophys. Res. Atm., 118(10): 4090-4106, doi:10.1002/jgrd.50229, 10.1002/jgrd.50229 * This study illustrates how the decadal climate response to strong volcanic eruptions depends on the background climate state at the time of the eruption and on the presence and magnitude of additional external forcings acting at the same time. It demonstrates that background climate conditions are not merely a source of additive noise for post-eruption decadal climate variability but actively influence the mechanisms involved in the post-eruption decadal evolution. * Khodri M., Izumo T., Vialard J., Janicot S., Cassou C., Lengaigne M., Mignot J., Gastineau G., E. Guilyardi, Lebas N., Robock A. and M.J McPhaden, Tropical explosive volcanic eruptions can trigger El Niño by cooling tropical Africa, Nature Communications, 8, 778 (2017). , 10.1038/s41467-017-00755-6 * This paper presents new evidences for a possible interference of volcanic forcing from tropical stratospheric eruptions on ENSO cycle and discusses the underlying physical processes. Targeted climate model simulations emphasize that Pinatubo-like eruptions tend to shorten La Niñas, lengthen El Niños and induce anomalous warming when occurring during neutral states. It also presents a new mechanisms suggesting that volcanically induced cooling in tropical Africa weakens the West African monsoon, and the resulting atmospheric Kelvin wave can drive equatorial westerly wind anomalies over the western Pacific. This wind anomaly is further amplified by air-sea interactions in the Pacific, favouring an El Niño-like response. * Stoffel M, Khodri M., Corona C., Guillet S., Poulain V., Bekki S., Guiot J., Luckman B.H., Oppenheimer C., Lebas N., Beniston M.& Masson-Delmotte V., Reconciling reconstructions and simulations of volcanic cooling, Nature Geoscience, 8, 784-788 (2015), 10.1038/NGEO2526, 2015 * The climatic impact of the largest volcanic events has been assessed in numerous modelling studies and tree-ring-based hemispheric temperature reconstructions. However, volcanic surface cooling derived from PMIP3 climate model simulations is systematically much stronger than the cooling seen in tree-ring-based proxies, suggesting that the proxies underestimate cooling; and/or the modelled forcing is unrealistically high. This paper present a new summer temperature reconstructions for the Northern Hemisphere from tree-ring width and maximum latewood density over the past 1,500 years in comparison to simulated climate effects of two large eruptions, in AD 1257 and 1815, using a climate model that accounts explicitly for self-limiting aerosol microphysical processes. Results reveal for the first time an agreement between modelled and tree-ring based reconstruction of mean Northern Hemisphere extra-tropical summer cooling over land estimated between 0.8 to 1.3 degC for these eruptions. This reconciliation of proxy and model evidence paves the way to improved assessment of the role of both past and future volcanism in climate forcing. * Schenk F., Väliranta M., Muschitiello F., Tarasov L., Heikkilä M., Björck S., Brandefelt J., Johansson A.V., Näslund J.O., Wohlfarth B. (2018): Warm summers during the Younger Dryas cold reversal. Nat. Communications 9:1634, https://doi.org/10.1038/s41467-018-04071-5 * Very cold North Atlantic Ocean states in response to a weak AMOC cause persistent atmospheric blocking over Europe during summer. Proxy-model evidence suggests warmer and very dry conditions in response to a slowdown of the AMOC consistent with observations since the 1980s. * Berman, AL., G. Silvestri, M. Rojas, M. Tonello, 2016: Accelerated greenhouse gases versus slow insolation forcing induced climate changes in southern South America since the Mid-Holocene. Climate Dynamics, 48(1-2): 387-404., 10.1007/s00382-016-3081-z * This paper describes past climates in South America combining multiproxyreconstructions and PMIP3 models to investigate the time evolution of regional climatic conditions from the Mid-Holocene (MH) to the present. * Berman, AL., G. Silvestri, M. Tonello, 2016: Differences between Last Glacial Maximum and present-day temperature and precipitation in southern South America. Quaternary Science Reviews. 150: 221 - 233., https://doi.org/10.1016/j.quascirev.2016.08.025 * This paper is the first analysis of differences between Last Glacial Maximum (LGM) and present climates in South America considering PMIP3 paleoclimatic models. * Berman, AL., G. Silvestri, M. Tonello, 2018: On the differences between Last Glacial Maximum and Mid-Holocene climates in southern South America simulated by PMIP3 models. Quaternary Science Reviews, 185: 113-121., https://doi.org/10.1016/j.quascirev.2018.02.003 * Differences between climate conditions during the Last Glacial Maximum and the Mid-Holocene in southern South America inferred from PMIP3 paleoclimatic simulations are described for the first time in this paper. * Hakim, G. J., J. Emile-Geay, E. J. Steig, D. Noone, D. M. Anderson, R. Tardif, N. Steiger, and W. A. Perkins (2016), The last millennium climate reanalysis project: Framework and first results, Journal of Geophysical Research: Atmospheres, 121, 6745 - 6764, 10.1002/2016JD024751 * Provides the first validated, global, multivariate reconstruction of climate fields based on a fusion of proxy and GCM runs. * Ault, T. R., C. Deser, M. Newman, and J. Emile- Geay (2013), Characterizing decadal to centennial variability in the equatorial pacific during the last millennium, Geophysical Research Letters, 40, 3450-3456, 10.1002/grl.50647 * Evaluates the ability of PMIP3-CMIP5 models to simulate tropical Pacific variability over the past millennium, as reconstructed from proxy data. The article identifies important disagreements between simulations and reconstructions: in the models, variability primarily reflects a thermodynamic response to reconstructed solar and volcanic activity, whereas in the reconstruction, variability arises from either internal climate processes, forced responses that differ from those in CCSM4, or non-climatic proxy processes that are not yet understood. These findings imply that the response of the tropical Pacific to future forcings may be even more uncertain than portrayed by CMIP5 because there are potentially important sources of century-scale variability that these models do not simulate. * Lambert, F., J.-S. Kug, R. J. Park, N. Mahowald, G. Winckler, A. Abe-Ouchi, R. O'ishi, T. Takemura, and J.-H. Lee (2013), The role of mineral-dust aerosols in polar temperature amplification, Nat. Clim. Chang., 3(5), 487-491, 10.1038/nclimate1785 * Impact of high atmospheric dust loads on polar temperature * Lambert, F., A. Tagliabue, G. Shaffer, F. Lamy, G. Winckler, L. Farias, L. Gallardo, and R. De Pol-Holz (2015), Dust fluxes and iron fertilization in Holocene and Last Glacial Maximum climates, Geophys. Res. Lett., 42(14), 6014-6023, 10.1002/2015GL064250 * Dust deposition fields for HOL and LGM climate, and associated CO2 drawdown through iron fertilization * García-García A., Cuesta-Valero F.J., Beltrami H. and Smerdon J.E. (2016). Simulation of air and ground temperatures in PMIP3/CMIP5 last millennium simulations: implications for climate reconstructions from borehole temperature profiles. Environmental Research Letter, 11(4):044022., https://doi.org/10.1088/1748-9326/11/4/044022 * This paper tests the methodology employed to reconstruct past ground surface temperature histories from borehole temperature profiles using simulations from the PMIP3/CMIP5 archives. * Cuesta-Valero F.J., García-García A., Beltrami H. and Smerdon J.E. (2016). First Assessment of Continental Energy Storage in CMIP5 Simulations. Geophysical Research Letters, 43., https://doi.org/10.1002/2016GL068496 * This paper assesses the ability of 30 CMIP5 models to reproduce the change in heat storage within the continental subsurface for the second half of the 20th century against estimates from borehole temperature profiles. * Cuesta-Valero, F. J., García-García, A., Beltrami, H., Zorita, E., and Jaume-Santero, F.: Long-term Surface Temperature (LoST) Database as a complement for GCM preindustrial simulations, Clim. Past Discuss., 2018., https://doi.org/10.5194/cp-2018-133 * A database containing long-term preindustrial absolute surface temperatures over North America is assembled and freely released for the use of the community. The long-term surface temperatures described here are estimated from geothermal data. These temperatures are useful for studying the stability of permafrost soils, as well as for evaluating the simulated preindustrial climatology, which may improve the estimated equilibrium climate sensitivity from climate models. * Yan Qing, Wei Ting, and Zhang Zhongshi, 2017: Variations in large-scale tropical cyclone genesis factors over the western North Pacific in the PMIP3 last millennium simulations, Climate Dynamics, 48(3-4): 957-970., n/a * This paper examines the variation of tropical cyclone genesis during the last millennium * 1. Charan Teja Tejavath, Ashok, K., Supriyo Chakraborty, and Ramesh Rengasamy, 2018: The Indian summer monsoon climate during the Last Millennium, as simulated by the PMIP3, passed discussion stage and under revision. Clim. Past Discuss., https://doi.org/10.5194/cp-2017-24, https://doi.org/10.5194/cp-2017-24 * All the PMIP3 models analysed (eight) in this study clearly show a relatively wet Indian summer monsoon conditions during medivial warm period. Moreover, this is notwithstanding that all these models show a relatively high frquency of El Ninos during this period, and a significant negative correlation between the interannual signals of ENSO and area-averaged Indian summer monsoon rainfall. This is due to a slow (multi-decadal to centennial) shift in Walker circulation apparently associated with external forcing, which reduces the ENSO impacts, which reduces the El Nino-associated anomolous reduction in the rainfall in various regions of the Indian sub-continent. This is the reason why the Indian summer monsoon was relatively wet within the last millenium.The results are relevant to the current day climate when the ENSO-monsoon relationship is weakening, and a shift in Walker circulation is recorded. * Melo-Aguilar, C., González-Rouco, J. F., García-Bustamante, E., Navarro-Montesinos, J., and Steinert, N.: Influence of radiative forcing factors on ground-air temperature coupling during the last millennium: implications for borehole climatology, Clim. Past, 14, 1583-1606, 2018., https://doi.org/10.5194/cp-14-1583-2018 * This paper assessed the long-term surface air temperature (SAT) and ground surface temperature (GST) coupling using simulations from the CESM-LME. It shows that this coupling can be impacted by long-term changes in the surface energy fluxes over the Last Millennium, due to the influence of anthropogenic external forcings, with potential implications for borehole-based temperature reconstructions. * Fernández-Donado, L. et al, 2013. Large-scale temperature response to external forcing in simulations and reconstructions of the last millennium. Climate of the Past, 9 (1), pp. 393-421., https://doi.org/10.5194/cp-9-393-2013 * This paper represents an extensive review of the state-of-the-art modelling and reconstructions effort for the last millennium (LM) previous to the coordinated approach within the CMIP5-PMIP3 community, as the basis of knowledge achieved prior the agreement of LM radiative forcings. Additionally, this work provides a quantitative framework to analyse the consistency between reconstructions and simulations in their response to external forcings and the respective role of the internal variability. * Zhang, H. et al, 2018. East Asian warm season temperature variations over the past two millennia. Scientific reports, 8 (1), p.7702., https://doi.org/10.1038/s41598-018-26038-8 * This work presents a spatially resolved warm-season temperature reconstruction for the last2k over the East Asian region showing the particular characteristics of climate variations during key periods of the last two thousand years and providing a comparison to PMIP3/CMIP5 climate model simulations. * Pavón-Carrasco, F.J. et al., 2018. Multi-centennial fluctuations of radionuclide production rates are modulated by the Earth's magnetic field. Scientific reports, 8(1), p.9820, https://doi.org/10.1038/s41598-018-28115-4 * A revision of the standard accepted assumptions to reconstruct the solar activity during the Holocene is presented in this work. It is shown that not only the solar magnetic field but also the geomagnetic field has a relevant role for the timescales of interest. The latter suggests the need of reviewing how past solar forcing estimations are obtained, with relevant implications for the solar-climate relation as well as for the present and future generation of paleo simulations. * Lowry, D.P. and Morrill, C. 2018. Is the Last Glacial Maximum a reverse analog for future hydroclimate changes in the Americas? Climate Dynamics., 10.1007/s00382-018-4385-y * Future hydroclimate change is expected to generally follow a wet-get-wetter, dry-get-drier (WWDD) pattern, yet key uncertainties remain regionally and over land. We analyze 6 PMIP3 LGM simulations and show that, in some regions of North and South America, LGM hydroclimate changes could provide some insight into future changes in precipitation-evaporation. * Loomis, S.E., Russell, J.M., Verschuren, D., Morrill, C., De Cort, G., Sinninghe Damste, J.S., Olago, D., Eggermont, H., Street-Perrott, F.A., Kelly, M.A. 2017. The tropical lapse rate steepened during the Last Glacial Maximum. Science Advances 3: e1600815., 10.1126/sciadv.1600815 * A new 25,000-year temperature reconstruction from Mount Kenya, East Africa, demonstrates that cooling during the Last Glacial Maximum was amplified with elevation. Comparison of our data with PMIP3 LGM simulations indicates that state-of-the-art models underestimate this lapse-rate change. * Morrill, C., Lowry, D.P., Hoell, A. 2018. Thermodynamic and dynamic causes of pluvial conditions during the Last Glacial Maximum in Western North America. Geophysical Research Letters 45, 335-345., 10.1002/2017GL075807 * We analyze 9 PMIP3 simulations to argue that wet conditions in western North America at LGM were caused by a combination of dynamic and thermodynamic factors. These same factors, working in the opposite direction, are projected to cause regional drying in western North America under increased greenhouse gas concentrations, indicating continuity from past to future in the mechanisms altering hydroclimate. * Biasutti, M., Voigt, A., Boos, W. R., Braconnot, P., Hargreaves, J. C., Harrison, S. P., et al. (2018). Global energetics and local physics as drivers of past, present and future monsoons. Nature Geoscience, 11(6), 1-11. , http://doi.org/10.1038/s41561-018-0137-1 * Global constraints on momentum and energy govern the variability of the rainfall belt in the intertropical convergence zone and the structure of the zonal mean tropical circulation. * Hargreaves, J. C., & Annan, J. D. (2016). Could the Pliocene constrain the equilibrium climate sensitivity? Climate of the Past, 12(8), 1591-1599. , http://doi.org/10.5194/cp-12-1591-2016 * The mid-Pliocene Warm Period (mPWP) is the most recent interval in which atmospheric carbon dioxide was substantially higher than in modern pre-industrial times. Here we analyse results from the PlioMIP and, for the first time, discuss the potential for this interval to usefully constrain the equilibrium climate sensitivity. * Annan, J. D., & Hargreaves, J. C. (2015). A perspective on model-data surface temperature comparison at the Last Glacial Maximum. Quaternary Science Reviews, 107, 1-10. , http://doi.org/10.1016/j.quascirev.2014.09.019 * We review progress in model and proxy-based reconstruction of the surface temperature field of the Last Glacial Maximum. The magnitudes of the large-scale changes are increasingly well-constrained, with a recent model-data synthesis generating a value of 4 C, which suggests a moderate equilibrium climate sensitivity of about 2.5 C. * Harrison, S. P., Bartlein, P. J., Izumi, K., Li, G., Annan, J., Hargreaves, J., et al. (2015). Evaluation of CMIP5 palaeo-simulations to improve climate projections. Nature Climate Change, 5(8), 735-743. , http://doi.org/10.1038/nclimate2649 * Past climate changes provide a unique opportunity for out-of-sample evaluation of model performance. Palaeo-evaluation has shown that the large-scale changes seen in twenty-first-century projections, including enhanced land-sea temperature contrast, latitudinal amplification, changes in temperature seasonality and scaling of precipitation with temperature, are likely to be realistic. * Wang, B., Li, J. and He, Q., 2017. Variable and robust East Asian monsoon rainfall response to El Niño over the past 60 years (1957-2016). Advances in Atmospheric Sciences, 34(10), pp.1235-1248., 10.1007/s00376-017-7016-3 * This paper revealed the nonstationarity of the ENSO-East Asian monsoon relationship. * Wang, B., Xiang, B., Li, J., Webster, P.J., Rajeevan, M.N., Liu, J. and Ha, K.J., 2015. Rethinking Indian monsoon rainfall prediction in the context of recent global warming. Nature communications, 6, p.7154., 10.1038/ncomms8154 * This work reveals Indian summer monsoon variability change over the past 147 years. * Wang, B., Lee, J.Y. and Xiang, B., 2015. Asian summer monsoon rainfall predictability: a predictable mode analysis. Climate Dynamics, 44(1-2), pp.61-74., 10.1007/s00382-014-2218-1 * Major modes of Asian summer monsoon rainfall variability and predictability are discussed in this paper. * Saint-Lu, M., et al. (2015). "Changes in the ENSO/SPCZ relationship from past to future climates." Earth and Planetary Science Letters 412: 18-24., http://doi.org/10.1016/j.epsl.2014.12.033 * This study considers a set of paleoclimate and future climate simulations. It shows that changes in the background tropical state largely control the mean SPCZ location. In contrast, changes in the background tropical state do not directly control the interannual variability of the SPCZ location. The relationship between ENSO and the SPCZ location varies from one climate to another. We thus demonstrate that the teleconnection mechanisms inferred from the modern climate cannot be directly extrapolated to other climates. This study therefore calls for a cautious interpretation of climate reconstructions from environmental indicators in the Southwest Pacific with regard to ENSO variations. * Blanchet, C. L., Contoux, C., Leduc, G.: Runoff and precipitation dynamics in the Blue and White Nile catchments during the mid-Holocene: a data-model comparison, Quaternary Science Reviews, 130, 222-230, doi: 10.1016/j.quascirev.2015.07.014, 2015., http://doi.org/10.1016/j.quascirev.2015.07.014 * This paper describes the changes in contribution between the White Nile and the Blue Nile river catchments during the mid-Holocene. By comparing regional proxy-records with the output from a global atmospheric model zoomed on Africa, we propose that the reduced contribution from the Blue Nile at 6 ka originated from both a higher White Nile runoff and a lower Blue Nile runoff. * Lu, Z., & Liu, Z. (2018). Orbital modulation of ENSO seasonal phase locking. Climate Dynamics., https://doi.org/10.1007/s00382-018-4382-1 * This paper shows the mechanisms how the timing of El Nino-Southern Oscillation peaks was modulated by orbital forcing, and calls for further investigation in CMIP6 ensembles for the future change of this phenomenon. * Lunt, D. J., A. Abe-Ouchi, P. Bakker, A. Berger, P. Braconnot, S. Charbit, N. Fischer, N. Herold, J. H. Jungclaus, V. C. Khon, U. Krebs-Kanzow, P. M. Langebroek, G. Lohmann, K. H. Nisancioglu, B. Otto-Bliesner, W. Park, M. Pfeiffer, S. J. Phipps, M. Prange, R. Rachmayani, H. Renssen, N. Rosenbloom, B. Schneider, E. J. Stone, K. Takahashi, W. Wei, Q. Yin and Z. S. Zhang: A multi-model assessment of last interglacial temperatures, Climate of the Past, 9, 699-717, doi:10.5194/cp-9-699-2013, 2013., 10.5194/cp-9-699-2013 * Examines the PMIP3 simulations of the Last Interglacial and finds that the models do not agree well with reconstructions. In particular, the models fail to replicate the reconstructed warming at high latitudes. * Schurer, A. P., G. C. Hegerl, M. E. Mann, S. F. B. Tett and S. J. Phipps: Separating Forced from Chaotic Climate Variability over the Past Millennium, Journal of Climate, 26, 6954-6973, doi:10.1175/JCLI-D-12-00826.1, 2013., 10.1175/JCLI-D-12-00826.1 * External forcings are found to contribute significantly towards long-term temperature variations over the last millennium, particularly from 1400 CE onwards. It is found that the recent observed 50- and 100-yr hemispheric temperature trends are substantially larger than estimates of the amplitude of internal climate variability. * Abram, N. J., R. Mulvaney, F. Vimeux, S. J. Phipps, J. Turner and M. H. England: Evolution of the Southern Annular Mode during the past millennium, Nature Climate Change, 4, 564-569, doi:10.1038/NCLIMATE2235, 2014., 10.1038/NCLIMATE2235 * Changes in the Southern Annular Mode over the last millennium are reconstructed. The SAM is found to have undergone a progressive shift towards its positive phase since the fifteenth century, causing cooling of the main Antarctic continent at the same time that the Antarctic Peninsula has warmed. The positive trend in the SAM since ~AD 1940 is reproduced by multi-model climate simulations forced with rising greenhouse gas levels and later ozone depletion, and the long-term average SAM index is now at its highest level for at least the past 1,000 years. * Bakker, P., V. Masson-Delmotte, B. Martrat, S. Charbit, H. Renssen, M. Gröger, U. Krebs-Kanzow, G. Lohman, D. J. Lunt, M. Pfeiffer, S. J. Phipps, M. Prange, S. P. Ritz, M. Schulz, B. Stenni, E. J. Stone and V. Varma: Temperature trends during the Present and Last Interglacial periods - a multi-model-data comparison, Quaternary Science Reviews, 99, 224-243, doi:10.1016/j.quascirev.2014.06.031, 2014., 10.1016/j.quascirev.2014.06.031 * The reconstructed Present Interglacial (PIG) and Last Interglacial (LIG) Northern Hemisphere mid-to-high latitude cooling compares well with multi-model, mean temperature trends for the warmest months and that these cooling trends reflect a linear response to the warmest-month insolation decrease over the interglacial intervals. The most notable exception is the strong LIG cooling trend reconstructed from Greenland ice cores that is not simulated by any of the models. A striking model-data mismatch is found for both the PIG and the LIG over large parts of the mid-to-high latitudes of the Southern Hemisphere where the data depicts negative temperature trends that are not in agreement with near zero trends in the simulations. * McGregor, H. V., M. N. Evans, H. Goosse, G. Leduc, B. Martrat, J. A. Addison, P. G. Mortyn, D. W. Oppo, M.-S. Seidenkrantz, M.-A. Sicre, S. J. Phipps, K. Selveraj, K. Thirumalai, H. L. Filipsson and V. Ersek: Robust global ocean cooling trend for the pre-industrial Common Era, Nature Geoscience, 8, 671-677, doi:10.1038/NGEO2510, 2015., 10.1038/NGEO2510 * Here we present a global synthesis of sea surface temperatures for the Common Era (CE) derived from 57 individual marine reconstructions that meet strict quality control criteria. We observe a cooling trend from 1 to 1800 CE that is robust against explicit tests for potential biases in the reconstructions. Climate simulations using single and cumulative forcings suggest that the ocean surface cooling trend from 801 to 1800 CE is not primarily a response to orbital forcing but arises from a high frequency of explosive volcanism. Our results show that repeated clusters of volcanic eruptions can induce a net negative radiative forcing that results in a centennial and global scale cooling trend via a decline in mixed-layer oceanic heat content. * Abram, N. J., H. V. McGregor, J. E. Tierney, M. N. Evans, N. P. McKay, D. S. Kaufman and the PAGES 2k Consortium (K. Thirumalai, B. Martrat, H. Goosse, S. J. Phipps, E. J. Steig, K. Halimeda Kilbourne, C. P. Saenger, J. Zinke, G. Leduc, J. A. Addison, P. Graham Mortyn, M.-S. Seidenkrantz, M.-A. Sicre, K. Selvaraj, H. L. Filipsson, R. Neukom, J. Gergis, M. A. J. Curran and L. von Gunten): Early onset of industrial-era warming across the oceans and continents, Nature, 536, 411-418, doi:10.1038/nature19082, 2016., 10.1038/nature19082 * Here we use post AD 1500 palaeoclimate records to show that sustained industrial-era warming of the tropical oceans first developed during the mid-nineteenth century and was nearly synchronous with Northern Hemisphere continental warming. The early onset of sustained, significant warming in palaeoclimate records and model simulations suggests that greenhouse forcing of industrial-era warming commenced as early as the mid-nineteenth century and included an enhanced equatorial ocean response mechanism. The development of Southern Hemisphere warming is delayed in reconstructions, but this apparent delay is not reproduced in climate simulations. Our findings imply that instrumental records are too short to comprehensively assess anthropogenic climate change and that, in some regions, about 180 years of industrial-era warming has already caused surface temperatures to emerge above pre-industrial values, even when taking natural variability into account. * Jungclaus, J. H., E. Bard, M. Baroni, P. Braconnot, J. Cao, L. P. Chini, T. Egorova, M. Evans, J. F. González-Rouco, H. Goosse, G. C. Hurtt, F. Joos, J. O. Kaplan, M. Khodri, K. K. Goldewijk, N. Krivova, A. N. LeGrande, S. J. Lorenz, J. Luterbacher, W. Man, A. C. Maycock, M. Meinshausen, A. Moberg, R. Muscheler, C. Nehrbass-Ahles, B. I. Otto-Bliesner, S. J. Phipps, J. Pongratz, E. Rozanov, G. A. Schmidt, H. Schmidt, W. Schmutz, A. Schurer, A. I. Shapiro, M. Sigl, J. E. Smerdon, S. K. Solanki, C. Timmreck, M. Toohey, I. G. Usoskin, S. Wagner, C.-J. Wu, K. L. Yeo, D. Zanchettin, Q. Zhang and E. Zorita: The PMIP4 contribution to CMIP6 - Part 3: The last millennium, scientific objective, and experimental design for the PMIP4 past1000 simulations, Geoscientific Model Development, 10, 4005-4033, doi:10.5194/gmd-10-4005-2017, 2017., 10.5194/gmd-10-4005-2017 * This paper describes the motivation and the experimental set-ups for the PMIP4-CMIP6 past1000 simulations, and discusses the forcing agents orbital, solar, volcanic, and land use/land cover changes, and variations in greenhouse gas concentrations. * Ackerley, D., J. Reeves, C. Barr, H. Bostock, K. Fitzsimmons, M.-S. Fletcher, C. Gouramanis, H. McGregor, S. Mooney, S. J. Phipps, J. Tibby and J. Tyler: Evaluation of PMIP2 and PMIP3 simulations of mid-Holocene climate in the Indo-Pacific, Australasian and Southern Ocean regions, Climate of the Past, 13, 1661-1684, doi:10.5194/cp-13-1661-2017, 2017., 10.5194/cp-13-1661-2017 * Shows that the PMIP2/PMIP3 models and proxies agree on the differences in climate state for 6 ka relative to 0 ka, when they are insolation driven. The largest uncertainty between the models and the proxies occurs over the Indo-Pacific Warm Pool (IPWP). * PAGES Hydro2k Consortium (J. E. Smerdon, J. Luterbacher, S. J. Phipps, K. J. Anchukaitis, T. Ault, S. Coats, K. M. Cobb, B. I. Cook, C. Colose, T. Felis, A. Gallant, J. H. Jungclaus, B. Konecky, A. LeGrande, S. Lewis, A. S. Lopatka, W. Man, J. S. Mankin, J. T. Maxwell, B. L. Otto-Bliesner, J. W. Partin, D. Singh, N. J. Steiger, S. Stevenson, J. E. Tierney, D. Zanchettin, H. Zhang, A. R. Atwood, L. Andreu-Hayles, S. H. Baek, B. Buckley, E. R. Cook, R. D'Arrigo, S. G. Dee, M. L. Griffiths, C. Kulkarni, Y. Kushnir, F. Lehner, C. Leland, H. W. Linderholm, A. Okazaki, J. Palmer, E. Piovano, C. C. Raible, M. P. Rao, J. Scheff, G. A. Schmidt, R. Seager, M. Widmann, A. P. Williams and E. Xoplaki): Comparing proxy and model estimates of hydroclimate variability and change over the Common Era, Climate of the Past, 13, 1851-1900, doi:10.5194/cp-13-1851-2017, 2017., 10.5194/cp-13-1851-2017 * We review the principal proxy data available for hydroclimatic reconstructionsover the Common Era (CE) and highlight the contemporary understanding of how these proxies are interpreted as hydroclimate indicators. We also review the available last-millennium simulations from fully coupled climate models and discuss several outstanding challenges associated with simulating hydroclimate variability and change over the CE. * Kageyama, M., P. Braconnot, S. P. Harrison, A. M. Haywood, J. H. Jungclaus, B. L. Otto-Bliesner, J.-Y. Peterschmitt, A. Abe-Ouchi, S. Albani, P. J. Bartlein, C. Brierley, M. Crucifix, A. Dolan, L. Fernandez-Donado, H. Fischer, P. O. Hopcroft, R. F. Ivanovic, F. Lambert, D. J. Lunt, N. M. Mahowald, W. R. Peltier, S. J. Phipps, D. M. Roche, G. A. Schmidt, L. Tarasov, P. J. Valdes, Q. Zhang and T. Zhou: The PMIP4 contribution to CMIP6 - Part 1: Overview and over-arching analysis plan, Geoscientific Model Development, 11, 1033-1057, doi:10.5194/gmd-11-1033-2018, 2018., 10.5194/gmd-11-1033-2018 * Simulations of five different periods have been designed to address the objectives of the sixth phase of the Coupled Model Intercomparison Project (CMIP6): the millennium prior to the industrial epoch (CMIP6 name: past1000); the mid-Holocene, 6000 years ago (midHolocene); the Last Glacial Maximum, 21 000 years ago (lgm); the Last Interglacial, 127 000 years ago (lig127k); and the mid-Pliocene Warm Period, 3.2 million years ago (midPliocene-eoi400). This paper describes the motivation for the choice of these periods and the design of the numerical experiments and database requests, with a focus on their novel features compared to the experiments performed in previous phases of PMIP and CMIP. It also outlines the analysis plan that takes advantage of the comparisons of the results across periods and across CMIP6 in collaboration with other MIPs. * Stenni, B., Curran, M. A. J., Abram, N. J., Orsi, A., Goursaud, S., Masson-Delmotte, V., Neukom, R., Goosse, H., Divine, D., Ommen, T. V., Steig, E. J., Dixon, D. A., Thomas, E. R., Bertler, N. A. N., Isaksson, E., Ekaykin, A., Werner, M. and Frezzotti, M.: Antarctic climate variability on regional and continental scales over the last 2000 years, Clim. Past, 13(11), 1609-1634, doi:10.5194/cp-13-1609-2017, 2017., 10.5194/cp-13-1609-2017 * The paper presents a most recent compilation of water stable isotope records from Antarctica, analysing climate variability on regional and continental scales over the last 2000 years. It shows that only for the Antarctic Peninsula the most recent century-scale warming trend is unusual in the context of natural variability over the last 2000 years. * Maier, E., Zhang, X., Werner, M., Gersonde, R., Mulitza, S., Méheust, M., Ren, J., Chapligin, B., Meyer, H., Stein, R., Tiedemann, R. and Lohmann, G.: North Pacific freshwater events linked to changes in glacial ocean circulation, Nature, 559(7713), 241-245, doi:10.1038/s41586-018-0276-y, 2018., 10.1038/s41586-018-0276-y * This study reveals that there was a strong connection between changes in North Atlantic circulation during Heinrich Stadials and injections of freshwater from the North American Cordilleran Ice Sheet to the north-eastern North Pacific. The results show that nonlinear ocean- atmosphere background interactions played a complex role in the dynamics linking the freshwater discharge responses of the North Atlantic and North Pacific during glacial periods. * Bartlein, P.J., and S.L. Shafer, 2018, Paleo calendar-effect adjustments in time-slice and transient climate-model simulations (PaleoCalAdjust v1.0): impact and strategies for data analysis. Geoscientific Model Development Discussions, 1-36., https://doi.org/10.5194/gmd-2018-283 * Implements an approach for adjusting for the paleo calendar effect, which is significant for the midHoloceneand lig127 PMIP experiments. * Biasutti, M., Voigt, A., Bader, J., Boos, W.R., Braconnot, P., Hargreaves, J.C., Harrison, S.P., Kang, S., Mapes, B., Scheff, J., Schumacher, C., Sobel, A.H., Schmidt, G., Xie, S-P. 2018. Global energetics and local physics as drivers of past, present and future monsoons. Nature Geosciences 11: 392-400. doi:10.1038/s41561-018-0137-1, doi:10.1038/s41561-018-0137-1 * provides a new theoretical framework for understanding changes in the monsoons * Atsawawaranunt, K., Comas-Bru, L., Amirnezhad Mozhdehi, S., Deininger, M., Harrison, S.P., Baker, A., Boyd, M., Kaushal, N., Masood Ahmed, S., Arienzo, M., Brahim, Y.A., Bajo, P., Braun, K., Burstyn, Y., Chawchai, S., Duan, W., Hatvani, I.G., Hu, J., Kern, Z., Labuhn, I., Lachniet, M., Lechleiter, F.A., Lorrey, A., Pérez-Mejías, C., Pickering, R., Scroxton, N. and SISAL Working Group Members, 2018. The SISAL database: a global resource to document water and carbon isotope records from speleothems. Earth System Science Data 10:1687-1713. , https://doi.org/10.5194/essd-10-1687-2018 * Documents a new data set of oxygen isotope data from speleothems that will can be used for benchmarking isotope-enabled palaeoclimate simulations * Prentice, I.C., Cleator, S.F., Huang, Y.F., Harrison, S.P., Roulstone, I., 2017. Reconstructing ice -age climates: quantifying low-CO2 effects on plants. Global and Planetary Change 149: 166-176., http://dx.doi.org/10.1016/j.gloplacha.2016.12.012 * Provides a way of taking account of the ecophysicological impacts of low CO2 during glacial periods in making climate reconstructions of moisture variables from fossil pollen. The water-use efficiency of plants in reduced under low CO2 and this results in vegetation appearing to reflect more arid conditions that in fact prevailed. The paper provides a correction which can be applied to existing pollen-based reconstructions of moisture to take account of this. * Sánchez Goñi, M.F., Desprat, S., Daniau, A.-L., Bassinot, F., Polanco-Martínez, J.M., Harrison, S.P., Allen, J.R.P., Anderson, R.S., Behling, H., Bonnefille, R., Burjachs, F., Carrión, J.S., Cheddadi, R., Clark, J.S., Combourieu-Nebout, N., Courtney-Mustaphi, C., Debusk, G.H., Dupont, L.M., Finch, J., Fletcher, W.J., Giardini, M., González, C., Gosling, W.D., Grigg, L.D., Grimm, E.C., Hayashi, R., Helmens, K., Heusser, L.E., Hill, T., Hope, G., Huntley, B., Igarashi, Y., Irino, T., Jacobs, B.F., Jiménez-Moreno, G., Kawai, S., Kershaw, P., Kumon, F., Lawson, I., Ledru, M.-P., Lézine, A.-M., Liew, P.-M., Magri, D., Marchant, R., Margari, V., Mayle, F., McKenzie, M., Moss, P., Müller, S., Müller, U.C., Naughton, F., Newnham, R.M., Oba, T., Pérez-Obiol, R., Pini, R., Ravazzi, C., Roucoux, K.H., Rucina, S., Scott, L., Takahara, H., Tzedakis, P.C., Urrego, D.H., Van Geel, B., Valencia, B.G., Vandergoes, M.J., Vincens , A., Whitlock, C.L., Willard, D. A., Yamamoto, M., 2017 The ACER pollen and charcoal database: a global resource to document vegetation and fire response to abrupt climate changes of the last glacial period. Earth System Science Data 9: 679-695., https://doi.org/10.5194/essd-9-679-2017 * Documents a global database of pollen and charcoal data which provides information on the response of vegetation and vegetation disturbance by fire to Dansgaard-Oeschger variability during the last glacial period. * Izumi, K. and P.J. Bartlein, 2016, North American paleoclimate reconstructions for the last glacial maximum using an inverse-modeling through iterative-forward-modeling (IMIFM) approach applied to pollen data. Geophysical Research Letters. 43:1-8, http://dx.doi.org/10.1002/2016GL070152 * Describes a method for interative forward-modeling reconstructions of paleoclimates * Harrison, S.P., P.J. Bartlein & I.C. Prentice, 2016, What have we learnt from palaeoclimate simulations? Journal of Quaternary Science31:363-385, https://doi.org/10.1002/jqs.2842 * Overview of results from comparisons of climate-model simulations and paleoclimatic data syntheses * Izumi, K., Bartlein, P.J., Harrison, S.P., 2015. Energy-balance mechanisms underlying consistent large-scale temperature responses in warm and cold climates. Climate Dynamics. 44:3111-3127., https://doi.org/10.1007/s00382-014-2189-2 * Explains the energy-balance sources of the large-scale temperature responses in warm and cold climates * Emile-Geay, J., Cobb, K.M., Carré, M., Braconnot, P., Leloup, J., Zhou, Y., Harrison, S.P., Corrège, T., Collins, M., Driscoll, R., Elliot, M., McGregor, H.V., Schneider, B., Tudhope, A., 2015. Linkages between tropical Pacific seasonal, interannual and orbital variability during the Holocene. Nature Geoscience 9: 168-173. doi:10.1038/ngeo2608, doi:10.1038/ngeo2608 * Shows that ENSO variance was reduced throughout most of the Holocene and that this quiescence is not obvioulsy related to orbital forcing. Climate models are unable to reproduce these observations. * Harrison, S.P., Bartlein, P.J., Brewer, S., Prentice, I.C., Boyd, M., Hessler, I., Holmgren, K., Izumi, K., Willis, K., 2014. Climate model benchmarking with glacial and mid-Holocene climates. Climate Dynamics 43, 671-688., https://doi.org/10.1007/s00382-013-1922-6 * Systematic benchmarking of the PMIP3 models * Hessler, I., Harrison, S.P., Kuchera, M., Waelbroeck, C., Chen, M-T., Anderson, C., de Vernal, A., Fréchette, B., Cloke-Hayes, A. and Londeix, L., 2014. Implication of methodological uncertainties for mid-Holocene sea surface temperature reconstructions. Climate of the Past 10: 2237-2252., https://doi.org/10.5194/cp-10-2237-2014 * Systematically assess the methodological issues thatcontribute to the uncertainties associated with sea-surface temperature reconstructions during the mid-Holocene. Indicates that the MH is not a good time period to evaluate oceanic conditions. * Perez-Sanz, A., Li, G., Gonzalez, P., Harrison, S.P., 2014. Evaluation of seasonal climates of northern Africa and the Mediterranean in the CMIP5 simulations. Climate of the Past 10: 551-568. doi:10.5194/cp-10-551-2014, doi:10.5194/cp-10-551-2014 * Provides an evaluation of the ability of the CMIP5 simulations to simukate enhanced monsoons during the mid-Holocene. * Izumi, K., P.J. Bartlein and S.P. Harrison, 2013, Consistent large-scale temperature responses in warm and cold climates, Geophysical Research Letters, https://dow.org/10.1002/grl.50350 * Demonstrates that there are consistent large-scale temperature responses in warm and cold climates using paleo simulations and reconstructions along with future simulations * Albani S., Balkanski Y., Mahowald N., Winckler G., Maggi V., Delmonte B.: Aerosol-climate interactions during the Last Glacial Maximum. Curr. Clim. Change Rep., 4, 99-114, doi:10.1007/s40641-018-0100-7, 2018., 10.1007/s40641-018-0100-7 * Recent invited review on aerosol-climate interaction during the LGM * Lambert, F., J.-S. Kug, R. J. Park, N. Mahowald, G. Winckler, A. Abe-Ouchi, R. O'ishi, T. Takemura, and J.-H. Lee (2013), The role of mineral-dust aerosols in polar temperature amplification, Nat. Clim. Chang., 3(5), 487-491, doi:10.1038/nclimate1785, 10.1038/nclimate1785 * Shows the polar amplification and potential radiative forcing effect of mineral dust aerosols. * Sánchez-Goñi, M.F., Bard, E., Landais, A., Rossignol, L., d'Errico, F. (2013). Air-sea temperature decoupling in Western Europe during the last interglacial/glacial transition. Nature Geoscience 6 , 837-841, DOI : 10.1038/ngeo1924 * In contrast with periods of relatively stable global ice volume (e.g. present-day interglacial), periods of ice-sheet growth are marked by a decoupling between eastern North Atlantic warming and European cooling. This configuration allows a northward shift of the westerlies bringing humidity to the high northern latitudes. * Zorzi, C., Sánchez Goñi, M.F., Anupama, K., Prasad, S., Hanquiez, V., Johnson, J., Giosan, L. (2015) Indian monsoon variations during three contrasting climatic periods: the Holocene, HeinrichStadial 2 and the last interglacial-glacial transition. Quaternary Science Reviews 125, 50-60., doi.org/10.1016/j.quascirev.2015.06.009 * Insolation changes control the long term trend of the Indian monsoon precipitation, but its millennial scale variability and intensity are instead modulated by atmospheric teleconnections to remote phenomena in the North Atlantic (e.g. amount of sea-ice or iceberg discharges), Eurasia or the Indian Ocean. * Sánchez Goñi, M.F., Rodrigues, T., Hodell, D.A., Polanco-Martinez, J.M., Alonso-Garcia, M., Hernandez-Almeida, I., Desprat, S., Ferretti, P. (2016) Tropically-driven climate shifts in southwestern Europe during MIS 19, a low excentricity interglacial. Earth and Planetary Science Letters 448, 81-93., http://dx.doi.org/10.1016/j.epsl.2016.05.018 * MIS 19, the best orbital analogue to our present interglacial, is marked by low latitude-driven 5000-yr cycles of drying and cooling in the western Mediterranean region, along with warmth in the subtropical gyre related to the fourth harmonic of precession. The discrepancy between the dominant cyclicity observed during MIS1, 2500-yr, and that of MIS19, 5000-yr, challenges the similar duration of the Holocene and MIS19c interglacials under natural boundary conditions. * Oliveira, D., Desprat, S., Yin, Q., Naughton, F., Trigo, R., Rodrigues, T., Abrantes, F., Sánchez Goñi, M.F. (2018). Unraveling the forcings controlling the vegetation and climate of the best orbital analogues for the present interglacial in SW Europe. Climate Dynamics 51, 667-686, doi:10.1007/s00382-017-3948-7 * Data-model comparison reveals that the SW Iberian forest dynamics over the best orbital analogues to our present interglacial are mostly coupled to changes in winter precipitation mainly controlled by precession, CO2 playing a negligible role. In contrast, the reconstructed lower forest optimum at MIS 19c is not reproduced by the simulations probably due to the lack of Eurasian ice sheets and its related feedbacks in the model. * Sánchez Goñi, M.F., Ferretti, P., Polanco-Martinez, J.M., Rodrigues, T., Alonso-Garcia, M., Rodriguez-Tovar, F.J., Dorador, J., Desprat, S. (2019). Pronounced northward shift of the westerlies during MIS 17 leading to the strong 100-kyr ice age cycles. Earth and Planetary Science Letters 511, 117-129., https://doi.org/10.1016/j.epsl.2019.01.032. * During MIS 17 (700 ka), a cold interglacial characterized by the lowest atmospheric CO2 concentrations of the last 800,000 years, the Iberian Peninsula was paradoxically marked by the maximum in the Mediterranean forest expansion indicating strong winter precipitation and summer warmth. These data indicate a decoupling between global and regional climates. This work also highlights the important contribution of the westerlies leading to the strong 100-kyr ice age cycles. These atmospheric changes remain, however, a key area of uncertainty in past and future climate model simulations. * Sánchez Goñi, M.F., Desprat, S., Daniau, A.-L., Bassinot, F., Polanco-Martinez, J.M., Harrison, S.P. and ACER contributors (2017). The ACER pollen and charcoal database : a global resource to document vegetation and fire response to abrupt climate changes during the last glacial period. Earth System Science Data, 9, 679-695., https://doi.org/10.5194/essd-9-679-2017 * This global vegetation and fire data compilation shows the regional response to rapid past climate changes comparable in velocity and magnitude to those expected in the 21st-century. ===== Chapter 3: Human influence on the climate system ===== Number of selected references: **13** * Kadow, C, S. Illing, O. Kunst, H. W. Rust, H. Pohlmann, W. A. Müller and U. Cubasch, 2015: Evaluation of forecasts by accuracy and spread in the MIKLIP decadal prediction system. Met. Z, DOI 10.1127/metz/2015/0639 * development of decadal prediction modeling * Bürger, G. and U. Cubasch, 2015: The detectability of climate engineering. J. Geophys. Res. Atmos., 120, , doi:10.1002/2015JD023954 * application of radiative forcing climate engineering * Kadow, C., S. Illing, I. Kröner, U. Ulbrich and U. Cubasch, 2017: Decadal climate predictions improved by ocean ensemble dispersion filtering. J. Adv. Model. Earth Syst. 9, doi 10.1002/2016M5000787 * recent mode development and its performance improvements * Bo Huang, U. Cubasch and C. Kadow, 2018: Seasonal prediction skill of East Asian summer monsoon in CMIP5 models. Earth Syst. Dynam., 9, 985-997,, doi: 10.5194/esd-9-985-2018 * evaluation of recent model experiments * Berman, AL., G. Silvestri, M. Rojas, M. Tonello, 2016: Accelerated greenhouse gases versus slow insolation forcing induced climate changes in southern South America since the Mid-Holocene. Climate Dynamics, 48(1-2): 387-404., 10.1007/s00382-016-3081-z * This paper describes past climates in South America combining multiproxyreconstructions and PMIP3 models to investigate the time evolution of regional climatic conditions from the Mid-Holocene (MH) to the present. * Berman, AL., G. Silvestri, M. Tonello, 2016: Differences between Last Glacial Maximum and present-day temperature and precipitation in southern South America. Quaternary Science Reviews. 150: 221 - 233., https://doi.org/10.1016/j.quascirev.2016.08.025 * This paper is the first analysis of differences between Last Glacial Maximum (LGM) and present climates in South America considering PMIP3 paleoclimatic models. * Luterbacher, J. and coauthors, 2016: European summer temperatures since Roman times. Environmental Research Letters, 11, 024001, doi:10.1088/1748-9326/11/2/024001 * A comparison with an ensemble of climate model simulations (PMIP5/CMIP3) suggests that the reconstructed European summer temperature variability over the period 850-2000CE reflects changes in both internal variability and external forcing on multi-decadal time-scales. * Abram, N. J., R. Mulvaney, F. Vimeux, S. J. Phipps, J. Turner and M. H. England: Evolution of the Southern Annular Mode during the past millennium, Nature Climate Change, 4, 564-569, doi:10.1038/NCLIMATE2235, 2014., 10.1038/NCLIMATE2235 * Changes in the Southern Annular Mode over the last millennium are reconstructed. The SAM is found to have undergone a progressive shift towards its positive phase since the fifteenth century, causing cooling of the main Antarctic continent at the same time that the Antarctic Peninsula has warmed. The positive trend in the SAM since ~AD 1940 is reproduced by multi-model climate simulations forced with rising greenhouse gas levels and later ozone depletion, and the long-term average SAM index is now at its highest level for at least the past 1,000 years. * McGregor, H. V., M. N. Evans, H. Goosse, G. Leduc, B. Martrat, J. A. Addison, P. G. Mortyn, D. W. Oppo, M.-S. Seidenkrantz, M.-A. Sicre, S. J. Phipps, K. Selveraj, K. Thirumalai, H. L. Filipsson and V. Ersek: Robust global ocean cooling trend for the pre-industrial Common Era, Nature Geoscience, 8, 671-677, doi:10.1038/NGEO2510, 2015., 10.1038/NGEO2510 * Here we present a global synthesis of sea surface temperatures for the Common Era (CE) derived from 57 individual marine reconstructions that meet strict quality control criteria. We observe a cooling trend from 1 to 1800 CE that is robust against explicit tests for potential biases in the reconstructions. Climate simulations using single and cumulative forcings suggest that the ocean surface cooling trend from 801 to 1800 CE is not primarily a response to orbital forcing but arises from a high frequency of explosive volcanism. Our results show that repeated clusters of volcanic eruptions can induce a net negative radiative forcing that results in a centennial and global scale cooling trend via a decline in mixed-layer oceanic heat content. * Abram, N. J., H. V. McGregor, J. E. Tierney, M. N. Evans, N. P. McKay, D. S. Kaufman and the PAGES 2k Consortium (K. Thirumalai, B. Martrat, H. Goosse, S. J. Phipps, E. J. Steig, K. Halimeda Kilbourne, C. P. Saenger, J. Zinke, G. Leduc, J. A. Addison, P. Graham Mortyn, M.-S. Seidenkrantz, M.-A. Sicre, K. Selvaraj, H. L. Filipsson, R. Neukom, J. Gergis, M. A. J. Curran and L. von Gunten): Early onset of industrial-era warming across the oceans and continents, Nature, 536, 411-418, doi:10.1038/nature19082, 2016., 10.1038/nature19082 * Here we use post AD 1500 palaeoclimate records to show that sustained industrial-era warming of the tropical oceans first developed during the mid-nineteenth century and was nearly synchronous with Northern Hemisphere continental warming. The early onset of sustained, significant warming in palaeoclimate records and model simulations suggests that greenhouse forcing of industrial-era warming commenced as early as the mid-nineteenth century and included an enhanced equatorial ocean response mechanism. The development of Southern Hemisphere warming is delayed in reconstructions, but this apparent delay is not reproduced in climate simulations. Our findings imply that instrumental records are too short to comprehensively assess anthropogenic climate change and that, in some regions, about 180 years of industrial-era warming has already caused surface temperatures to emerge above pre-industrial values, even when taking natural variability into account. * Jungclaus, J. H., E. Bard, M. Baroni, P. Braconnot, J. Cao, L. P. Chini, T. Egorova, M. Evans, J. F. González-Rouco, H. Goosse, G. C. Hurtt, F. Joos, J. O. Kaplan, M. Khodri, K. K. Goldewijk, N. Krivova, A. N. LeGrande, S. J. Lorenz, J. Luterbacher, W. Man, A. C. Maycock, M. Meinshausen, A. Moberg, R. Muscheler, C. Nehrbass-Ahles, B. I. Otto-Bliesner, S. J. Phipps, J. Pongratz, E. Rozanov, G. A. Schmidt, H. Schmidt, W. Schmutz, A. Schurer, A. I. Shapiro, M. Sigl, J. E. Smerdon, S. K. Solanki, C. Timmreck, M. Toohey, I. G. Usoskin, S. Wagner, C.-J. Wu, K. L. Yeo, D. Zanchettin, Q. Zhang and E. Zorita: The PMIP4 contribution to CMIP6 - Part 3: The last millennium, scientific objective, and experimental design for the PMIP4 past1000 simulations, Geoscientific Model Development, 10, 4005-4033, doi:10.5194/gmd-10-4005-2017, 2017., 10.5194/gmd-10-4005-2017 * This paper describes the motivation and the experimental set-ups for the PMIP4-CMIP6 past1000 simulations, and discusses the forcing agents orbital, solar, volcanic, and land use/land cover changes, and variations in greenhouse gas concentrations. * PAGES Hydro2k Consortium (J. E. Smerdon, J. Luterbacher, S. J. Phipps, K. J. Anchukaitis, T. Ault, S. Coats, K. M. Cobb, B. I. Cook, C. Colose, T. Felis, A. Gallant, J. H. Jungclaus, B. Konecky, A. LeGrande, S. Lewis, A. S. Lopatka, W. Man, J. S. Mankin, J. T. Maxwell, B. L. Otto-Bliesner, J. W. Partin, D. Singh, N. J. Steiger, S. Stevenson, J. E. Tierney, D. Zanchettin, H. Zhang, A. R. Atwood, L. Andreu-Hayles, S. H. Baek, B. Buckley, E. R. Cook, R. D'Arrigo, S. G. Dee, M. L. Griffiths, C. Kulkarni, Y. Kushnir, F. Lehner, C. Leland, H. W. Linderholm, A. Okazaki, J. Palmer, E. Piovano, C. C. Raible, M. P. Rao, J. Scheff, G. A. Schmidt, R. Seager, M. Widmann, A. P. Williams and E. Xoplaki): Comparing proxy and model estimates of hydroclimate variability and change over the Common Era, Climate of the Past, 13, 1851-1900, doi:10.5194/cp-13-1851-2017, 2017., 10.5194/cp-13-1851-2017 * We review the principal proxy data available for hydroclimatic reconstructionsover the Common Era (CE) and highlight the contemporary understanding of how these proxies are interpreted as hydroclimate indicators. We also review the available last-millennium simulations from fully coupled climate models and discuss several outstanding challenges associated with simulating hydroclimate variability and change over the CE. * Gallego-Sala, A., Charman, D., Harrison, S.P., Li, G. and Prentice, I.C., 2016. Climate-driven expansion of blanket bogs in Britain during the Holocene. Climate of the Past 12: 129-136., https://doi.org/10.5194/cp-12-129-2016 * Shows that the Late Holocene expansion of peat bogs across Britain, often attributed to human activities, can in fact be explained by climate changes. ===== Chapter 4: Future global climate: scenario-based projections and near-term information ===== Number of selected references: **25** * Brierley, C., & Wainer, I. (2018). Inter-annual variability in the tropical Atlantic from the Last Glacial Maximum into future climate projections simulated by CMIP5/PMIP3. Climate of the Past, 14(10), 1377-1390., https://doi.org/10.5194/cp-14-1377-2018 * We look at changes in two climate modes (Atlantic Nino and Atlantic Meridional Mode) and how they respond to past/future forcing. Whilst there are robust changes not obvious constraints emerge across the ensemble . * Sun, Y. et al.,2013:A comparative study of large-scale atmospheric circulation in the context of a future scenario (RCP4.5) and past warmth (mid-Pliocene), Climate of the Past, 9, 1613-1627., https://doi.org/10.5194/cp-9-1613-2013 * This study demonstrate the issue"Is tropical atmospheric circulation changes in mid-Pliocene warm climate an analogue for the future projection". * Fasullo, J.T., R. Tomas, S. Stevenson, B. Otto-Bliesner, E. Brady, E. Wahl, 2017: The amplifying influence of increased ocean stratification on a future year without a summer, Nature Communications, 8, 1236. doi:10.1038/s41467-017-01302-z, https://doi.org/10.1038/s41467-017-01302-z * CESM simulations of both the 1815 Tambora eruption and a hypothetical analogous future eruption are compared, the latter occurring in 2085 assuming a business-as-usual climate scenario. The 1815 eruption drove strong responses in both the ocean and cryosphere that were fundamental to driving the Year-Without-A-Summer. Through modulation of ocean stratification and near-surface winds, global warming contributes to an amplified surface climate response in CESM. * Kadow, C, S. Illing, O. Kunst, H. W. Rust, H. Pohlmann, W. A. Müller and U. Cubasch, 2015: Evaluation of forecasts by accuracy and spread in the MIKLIP decadal prediction system. Met. Z, DOI 10.1127/metz/2015/0639 * development of decadal prediction modeling * Bürger, G. and U. Cubasch, 2015: The detectability of climate engineering. J. Geophys. Res. Atmos., 120, , doi:10.1002/2015JD023954 * application of radiative forcing climate engineering * Stoffel M, Khodri M., Corona C., Guillet S., Poulain V., Bekki S., Guiot J., Luckman B.H., Oppenheimer C., Lebas N., Beniston M.& Masson-Delmotte V., Reconciling reconstructions and simulations of volcanic cooling, Nature Geoscience, 8, 784-788 (2015), 10.1038/NGEO2526, 2015 * The climatic impact of the largest volcanic events has been assessed in numerous modelling studies and tree-ring-based hemispheric temperature reconstructions. However, volcanic surface cooling derived from PMIP3 climate model simulations is systematically much stronger than the cooling seen in tree-ring-based proxies, suggesting that the proxies underestimate cooling; and/or the modelled forcing is unrealistically high. This paper present a new summer temperature reconstructions for the Northern Hemisphere from tree-ring width and maximum latewood density over the past 1,500 years in comparison to simulated climate effects of two large eruptions, in AD 1257 and 1815, using a climate model that accounts explicitly for self-limiting aerosol microphysical processes. Results reveal for the first time an agreement between modelled and tree-ring based reconstruction of mean Northern Hemisphere extra-tropical summer cooling over land estimated between 0.8 to 1.3 degC for these eruptions. This reconciliation of proxy and model evidence paves the way to improved assessment of the role of both past and future volcanism in climate forcing. * Sun, Y. et al., 2018:Quantifying East Asian summer monsoon dynamics in the ECP4.5 scenario with reference to the mid-Piacenzian warm period. Geophysical Research Letters , https://doi.org/10.1029/2018GL080061 * A comparison of summer monsoon dynamics over East Asia for the mid-Piacenzian and the ECP4.5 scenario reveals both large-scale similarities and regional differences. a) Large-scale similarity in moisture transport under thermal control b) Regional differences in vertical motion regulated by moist static energy c) Negligible effect of slight topographic difference on regional precipitation * Emile-Geay, J., K. M. Cobb, M. Carre, P. Braconnot, J. Leloup, Y. Zhou, S. P. Harrison, T. Correge,H. V. McGregor, M. Collins, R. Driscoll, M. Elliot, B. Schneider, and A. Tudhope (2016), Links betweentropical pacific seasonal, interannual and orbital variability during the holocene, Nature Geosci, 9(2),168-173, 10.1038/ngeo2608 * This paper evaluates PMIP3 models and their ability to simulate the observed relationship between ENSO and the seasonal cycle on orbital scales. It reveals a fundamental discrepancy between models and observations that is critical to understanding the simulated ENSO response to future GHG emissions. * Ault, T. R., C. Deser, M. Newman, and J. Emile- Geay (2013), Characterizing decadal to centennial variability in the equatorial pacific during the last millennium, Geophysical Research Letters, 40, 3450-3456, 10.1002/grl.50647 * Evaluates the ability of PMIP3-CMIP5 models to simulate tropical Pacific variability over the past millennium, as reconstructed from proxy data. The article identifies important disagreements between simulations and reconstructions: in the models, variability primarily reflects a thermodynamic response to reconstructed solar and volcanic activity, whereas in the reconstruction, variability arises from either internal climate processes, forced responses that differ from those in CCSM4, or non-climatic proxy processes that are not yet understood. These findings imply that the response of the tropical Pacific to future forcings may be even more uncertain than portrayed by CMIP5 because there are potentially important sources of century-scale variability that these models do not simulate. * Lowry, D.P. and Morrill, C. 2018. Is the Last Glacial Maximum a reverse analog for future hydroclimate changes in the Americas? Climate Dynamics., 10.1007/s00382-018-4385-y * Future hydroclimate change is expected to generally follow a wet-get-wetter, dry-get-drier (WWDD) pattern, yet key uncertainties remain regionally and over land. We analyze 6 PMIP3 LGM simulations and show that, in some regions of North and South America, LGM hydroclimate changes could provide some insight into future changes in precipitation-evaporation. * Loomis, S.E., Russell, J.M., Verschuren, D., Morrill, C., De Cort, G., Sinninghe Damste, J.S., Olago, D., Eggermont, H., Street-Perrott, F.A., Kelly, M.A. 2017. The tropical lapse rate steepened during the Last Glacial Maximum. Science Advances 3: e1600815., 10.1126/sciadv.1600815 * A new 25,000-year temperature reconstruction from Mount Kenya, East Africa, demonstrates that cooling during the Last Glacial Maximum was amplified with elevation. Comparison of our data with PMIP3 LGM simulations indicates that state-of-the-art models underestimate this lapse-rate change. * Morrill, C., Lowry, D.P., Hoell, A. 2018. Thermodynamic and dynamic causes of pluvial conditions during the Last Glacial Maximum in Western North America. Geophysical Research Letters 45, 335-345., 10.1002/2017GL075807 * We analyze 9 PMIP3 simulations to argue that wet conditions in western North America at LGM were caused by a combination of dynamic and thermodynamic factors. These same factors, working in the opposite direction, are projected to cause regional drying in western North America under increased greenhouse gas concentrations, indicating continuity from past to future in the mechanisms altering hydroclimate. * Biasutti, M., Voigt, A., Boos, W. R., Braconnot, P., Hargreaves, J. C., Harrison, S. P., et al. (2018). Global energetics and local physics as drivers of past, present and future monsoons. Nature Geoscience, 11(6), 1-11. , http://doi.org/10.1038/s41561-018-0137-1 * Global constraints on momentum and energy govern the variability of the rainfall belt in the intertropical convergence zone and the structure of the zonal mean tropical circulation. * Wang, B., Li, J., Cane, M.A., Liu, J., Webster, P.J., Xiang, B., Kim, H.M., Cao, J. and Ha, K.J., 2018. Toward Predicting Changes in the Land Monsoon Rainfall a Decade in Advance. Journal of Climate, 31(7), pp.2699-2714., 10.1175/JCLI-D-17-0521.1 * This paper pointed out the sources of multidecadal predictability for the Northern Hemisphere land monsoon rainfall, which is closely related to the near-term predictability of the future climate. * Xiang, B., Wang, B., Li, J., Zhao, M. and Lee, J.Y., 2014. Understanding the anthropogenically forced change of equatorial Pacific trade winds in coupled climate models. Journal of Climate, 27(22), pp.8510-8526., 10.1175/JCLI-D-14-00115.1 * This paper discussed how and why anthropogenic forcing will change the trade winds. * Lee, J.Y., Wang, B., Seo, K.H., Kug, J.S., Choi, Y.S., Kosaka, Y. and Ha, K.J., 2014. Future change of Northern Hemisphere summer tropical-extratropical teleconnection in CMIP5 models. Journal of Climate, 27(10), pp.3643-3664., 10.1175/JCLI-D-13-00261.1 * The circumglobal teleconnection pattern is a dominant mode of the Northern Hemisphere summer circulation variability. This work documents its future change. * Lee, J.Y. and Wang, B., 2014. Future change of global monsoon in the CMIP5. Climate Dynamics, 42(1-2), pp.101-119., 10.1007/s00382-012-1564-0 * Global monsoon is a fundamental mode of global climate, and this work discusses its future change. * Wang, B., Yim, S.Y., Lee, J.Y., Liu, J. and Ha, K.J., 2014. Future change of Asian-Australian monsoon under RCP 4.5 anthropogenic warming scenario. Climate dynamics, 42(1-2), pp.83-100., 10.1007/s00382-013-1769-x * The Asian-Australian monsoon is the most important mode of Earth climate system; this work discusses the projected future change of this system. * Murakami, H., Wang, B., Li, T. and Kitoh, A., 2013. Projected increase in tropical cyclones near Hawaii. Nature Climate Change, 3(8), p.749., 10.1038/NCLIMATE1890 * This paper discussed future change of the tropical cyclones in the central Pacific. * Wang, B., Liu, J., Kim, H.J., Webster, P.J., Yim, S.Y. and Xiang, B., 2013. Northern Hemisphere summer monsoon intensified by mega-El Niño/southern oscillation and Atlantic multidecadal oscillation. Proceedings of the National Academy of Sciences, 110(14), pp.5347-5352., 10.1073/pnas.1219405110 * This paper revealed the sources of predictability of decadal-multidecadal variation as well as the anthropogenic effects on recent change of the Northern Hemisphere summer monsoon, which is relevant to the near-term prediction of the future climate. * Lu, Z., & Liu, Z. (2018). Orbital modulation of ENSO seasonal phase locking. Climate Dynamics., https://doi.org/10.1007/s00382-018-4382-1 * This paper shows the mechanisms how the timing of El Nino-Southern Oscillation peaks was modulated by orbital forcing, and calls for further investigation in CMIP6 ensembles for the future change of this phenomenon. * Abram, N. J., H. V. McGregor, J. E. Tierney, M. N. Evans, N. P. McKay, D. S. Kaufman and the PAGES 2k Consortium (K. Thirumalai, B. Martrat, H. Goosse, S. J. Phipps, E. J. Steig, K. Halimeda Kilbourne, C. P. Saenger, J. Zinke, G. Leduc, J. A. Addison, P. Graham Mortyn, M.-S. Seidenkrantz, M.-A. Sicre, K. Selvaraj, H. L. Filipsson, R. Neukom, J. Gergis, M. A. J. Curran and L. von Gunten): Early onset of industrial-era warming across the oceans and continents, Nature, 536, 411-418, doi:10.1038/nature19082, 2016., 10.1038/nature19082 * Here we use post AD 1500 palaeoclimate records to show that sustained industrial-era warming of the tropical oceans first developed during the mid-nineteenth century and was nearly synchronous with Northern Hemisphere continental warming. The early onset of sustained, significant warming in palaeoclimate records and model simulations suggests that greenhouse forcing of industrial-era warming commenced as early as the mid-nineteenth century and included an enhanced equatorial ocean response mechanism. The development of Southern Hemisphere warming is delayed in reconstructions, but this apparent delay is not reproduced in climate simulations. Our findings imply that instrumental records are too short to comprehensively assess anthropogenic climate change and that, in some regions, about 180 years of industrial-era warming has already caused surface temperatures to emerge above pre-industrial values, even when taking natural variability into account. * Prado, L. F., Wainer, I., Chiessi, C. M. (2013). Mid-Holocene PMIP3/CMIP5 model results: Intercomparison for the South American Monsoon System. The Holocene, Vol 23, Issue 12, 1915-1920., 10.1177/0959683613505336 * This paper contains an unpdated proxy compilation for South American Monsoon System during the Mid-Holocene, and also a data-model comparison using the PMIP3 models. * Chandan and Peltier 2018: On the mechanisms of warming the mid-Pliocene and the inference of a hierarchy of climate sensitivities with relevance to the understanding of climate futures. Climate of the past, 14, 825-856, https://doi.org/10.5194/cp-14-825-2018 * This paper derives a hierarchy of climate sensitivities, applicable on various timescales, from modelling studies of the future-like warm period of the mid-Pliocene. * Sánchez Goñi, M.F., Ferretti, P., Polanco-Martinez, J.M., Rodrigues, T., Alonso-Garcia, M., Rodriguez-Tovar, F.J., Dorador, J., Desprat, S. (2019). Pronounced northward shift of the westerlies during MIS 17 leading to the strong 100-kyr ice age cycles. Earth and Planetary Science Letters 511, 117-129., https://doi.org/10.1016/j.epsl.2019.01.032. * During MIS 17 (700 ka), a cold interglacial characterized by the lowest atmospheric CO2 concentrations of the last 800,000 years, the Iberian Peninsula was paradoxically marked by the maximum in the Mediterranean forest expansion indicating strong winter precipitation and summer warmth. These data indicate a decoupling between global and regional climates. This work also highlights the important contribution of the westerlies leading to the strong 100-kyr ice age cycles. These atmospheric changes remain, however, a key area of uncertainty in past and future climate model simulations. ===== Chapter 5: Global carbon and other biogeochemical cycles and feedbacks ===== Number of selected references: **9** * Lambert, F., A. Tagliabue, G. Shaffer, F. Lamy, G. Winckler, L. Farias, L. Gallardo, and R. De Pol-Holz (2015), Dust fluxes and iron fertilization in Holocene and Last Glacial Maximum climates, Geophys. Res. Lett., 42(14), 6014-6023, 10.1002/2015GL064250 * Dust deposition fields for HOL and LGM climate, and associated CO2 drawdown through iron fertilization * Lu, Z., Miller, P. A., Zhang, Q., Zhang, Q., Wårlind, D., Nieradzik, L., & Smith, B. (2018). Dynamic Vegetation Simulations of the Mid-Holocene Green Sahara. Geophysical Research Letters, 45(16), 8294-8303., https://doi.org/10.1029/2018GL079195 * This paper shows that the simulated vegetation composition in Sahara/Sahel, and in turn, atmosphere and vegetation feedbacks, depend on the correct representation of fire disturbance and soil texture in a humid environment. * Gray, W.R., Rae, J.W.B, Wills, R.C.J., Shevenell, A.E., Taylor, B., Burke, A., Foster, G.L., Lear, C.H., 2018. Deglacial upwelling, productivity and CO2 outgassing in the North Pacific Ocean. Nature Geoscience 11, 340-344. , https://doi.org/10.1038/s41561-018-0108-6 * This paper assess response of atmospheric circulations to LGM ice sheet forcing to understand controls on biogeochemistry of the North Pacific Ocean during last deglaciation. The paper suggests massive CO2 outgassing from the North Pacific during the last deglaciation was aided by a large increase in Ekman suction within the North Pacific with the presence of an ice sheet over North America. * Harrison, S. P., Bartlein, P. J., Brovkin, V., Houweling, S., Kloster, S., & Prentice, I. C. (2018). The biomass burning contribution to climate-carbon-cycle feedback. Earth Syst. Dynam., 9(2), 663-677., https://doi.org/10.5194/esd-9-663-2018 * Quantifies the biomass burning contribution to climate-carbon-cycle feedback * Li, G., Gerhart, L.M., Harrison, S.P., Ward, J., Harris, J., and Prentice, I.C., 2017. Changes in biomass allocation buffer low CO2 effects on tree growth during the last glaciation. Nature Scientific Reports 7, 43087., doi: 10.1038/srep43087. * Shows that changes in carbon allocation between above- and below-ground components are necessary to explain tree growth under low CO2 conditions during the glacial. This has implications both for modelling vegetation, since current models assume that allocation is a fixed ratio, and for interpreting tree ring records as a climate signal. * Martin Calvo, M., Prentice, I.C., Harrison, S.P., 2014. Climate versus carbon dioxide controls on biomass burning: a model analysis of the glacial-interglacial contrast. Biogeosciences, 11, 6017-6027. doi:10.5194/bg-11-6017-2014, doi:10.5194/bg-11-6017-2014a * Demonstrates that changing CO2 since the Last Glacial Maximum has affected fire regimes through altering productivity and hence fuel loads. By analogy, both rising CO2 and climate must be considered as risk factors for wildfire. * Albani S., Balkanski Y., Mahowald N., Winckler G., Maggi V., Delmonte B.: Aerosol-climate interactions during the Last Glacial Maximum. Curr. Clim. Change Rep., 4, 99-114, doi:10.1007/s40641-018-0100-7, 2018., 10.1007/s40641-018-0100-7 * Recent invited review on aerosol-climate interaction during the LGM * Yamamoto, A., Abe-Ouchi, A., Ohgaito, R., Ito, A., and Oka, A., 2019: Glacial CO2 decrease and deep-water deoxygenation by iron fertilization from glaciogenic dust. Climate of the Past, 15, 981-996., https://doi.org/10.5194/cp-15-981-2019 * This paper reports our numerical simulation which successfully reproduces records of glacial oxygen changes and shows the significance of iron supply from glaciogenic dust. Our model simulations clarify that the enhanced efficiency of the biological pump is responsible for glacial CO2 decline of more than 30 ppm and approximately half of deep-ocean deoxygenation. * Lambert, F., A. Tagliabue, G. Shaffer, F. Lamy, G. Winckler, L. Farias, L. Gallardo, and R. De Pol-Holz (2015), Dust fluxes and iron fertilization in Holocene and Last Glacial Maximum climates, Geophys. Res. Lett., 42(14), 6014-6023, doi:10.1002/2015GL064250, 10.1002/2015GL064250 * Shows the potential for increased dust depositions to reduce global CO2 concentrations ===== Chapter 6: Short-Lived Climate Forcers ===== Number of selected references: **17** * Zanchettin, D., Khodri, M., Timmreck, C., Toohey, M., Schmidt, A., Gerber, E. P., Hegerl, G., Robock, A., Pausata, F. S. R., Ball, W. T., Bauer, S. E., Bekki, S., Dhomse, S. S., LeGrande, A. N., Mann, G. W., Marshall, L., Mills, M., Marchand, M., Niemeier, U., Poulain, V., Rozanov, E., Rubino, A., Stenke, A., Tsigaridis, K., and Tummon, F.: The Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP): experimental design and forcing input data for CMIP6, Geosci. Model Dev., 9, 2701-2719, doi:10.5194/gmd-9-2701-2016, 2016, 10.5194/gmd-9-2701-2016, 2016 * This paper presents the experimental design of the "Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP), which includes idealized experiments focused on the short-term atmospheric as well as long-term coupled response to volcanic forcing. The core idea of VolMIP is to constrain radiative forcing among the participating models to focus on the climatic response, hence reference forcing dataare provided in terms of optical aerosol properties for a series of reference eruptions. * Zanchettin, D., O. Bothe, H. F. Graf, S. J. Lorenz, J. Luterbacher, C. Timmreck, and J. H. Jungclaus (2013) Background conditions influence the decadal climate response to strong volcanic eruptions. J. Geophys. Res. Atm., 118(10): 4090-4106, doi:10.1002/jgrd.50229, 10.1002/jgrd.50229 * This study illustrates how the decadal climate response to strong volcanic eruptions depends on the background climate state at the time of the eruption and on the presence and magnitude of additional external forcings acting at the same time. It demonstrates that background climate conditions are not merely a source of additive noise for post-eruption decadal climate variability but actively influence the mechanisms involved in the post-eruption decadal evolution. * Khodri M., Izumo T., Vialard J., Janicot S., Cassou C., Lengaigne M., Mignot J., Gastineau G., E. Guilyardi, Lebas N., Robock A. and M.J McPhaden, Tropical explosive volcanic eruptions can trigger El Niño by cooling tropical Africa, Nature Communications, 8, 778 (2017). , 10.1038/s41467-017-00755-6 * This paper presents new evidences for a possible interference of volcanic forcing from tropical stratospheric eruptions on ENSO cycle and discusses the underlying physical processes. Targeted climate model simulations emphasize that Pinatubo-like eruptions tend to shorten La Niñas, lengthen El Niños and induce anomalous warming when occurring during neutral states. It also presents a new mechanisms suggesting that volcanically induced cooling in tropical Africa weakens the West African monsoon, and the resulting atmospheric Kelvin wave can drive equatorial westerly wind anomalies over the western Pacific. This wind anomaly is further amplified by air-sea interactions in the Pacific, favouring an El Niño-like response. * Stoffel M, Khodri M., Corona C., Guillet S., Poulain V., Bekki S., Guiot J., Luckman B.H., Oppenheimer C., Lebas N., Beniston M.& Masson-Delmotte V., Reconciling reconstructions and simulations of volcanic cooling, Nature Geoscience, 8, 784-788 (2015), 10.1038/NGEO2526, 2015 * The climatic impact of the largest volcanic events has been assessed in numerous modelling studies and tree-ring-based hemispheric temperature reconstructions. However, volcanic surface cooling derived from PMIP3 climate model simulations is systematically much stronger than the cooling seen in tree-ring-based proxies, suggesting that the proxies underestimate cooling; and/or the modelled forcing is unrealistically high. This paper present a new summer temperature reconstructions for the Northern Hemisphere from tree-ring width and maximum latewood density over the past 1,500 years in comparison to simulated climate effects of two large eruptions, in AD 1257 and 1815, using a climate model that accounts explicitly for self-limiting aerosol microphysical processes. Results reveal for the first time an agreement between modelled and tree-ring based reconstruction of mean Northern Hemisphere extra-tropical summer cooling over land estimated between 0.8 to 1.3 degC for these eruptions. This reconciliation of proxy and model evidence paves the way to improved assessment of the role of both past and future volcanism in climate forcing. * Lambert, F., J.-S. Kug, R. J. Park, N. Mahowald, G. Winckler, A. Abe-Ouchi, R. O'ishi, T. Takemura, and J.-H. Lee (2013), The role of mineral-dust aerosols in polar temperature amplification, Nat. Clim. Chang., 3(5), 487-491, 10.1038/nclimate1785 * Impact of high atmospheric dust loads on polar temperature * Lambert, F., A. Tagliabue, G. Shaffer, F. Lamy, G. Winckler, L. Farias, L. Gallardo, and R. De Pol-Holz (2015), Dust fluxes and iron fertilization in Holocene and Last Glacial Maximum climates, Geophys. Res. Lett., 42(14), 6014-6023, 10.1002/2015GL064250 * Dust deposition fields for HOL and LGM climate, and associated CO2 drawdown through iron fertilization * Schurer, A. P., G. C. Hegerl, M. E. Mann, S. F. B. Tett and S. J. Phipps: Separating Forced from Chaotic Climate Variability over the Past Millennium, Journal of Climate, 26, 6954-6973, doi:10.1175/JCLI-D-12-00826.1, 2013., 10.1175/JCLI-D-12-00826.1 * External forcings are found to contribute significantly towards long-term temperature variations over the last millennium, particularly from 1400 CE onwards. It is found that the recent observed 50- and 100-yr hemispheric temperature trends are substantially larger than estimates of the amplitude of internal climate variability. * Abram, N. J., R. Mulvaney, F. Vimeux, S. J. Phipps, J. Turner and M. H. England: Evolution of the Southern Annular Mode during the past millennium, Nature Climate Change, 4, 564-569, doi:10.1038/NCLIMATE2235, 2014., 10.1038/NCLIMATE2235 * Changes in the Southern Annular Mode over the last millennium are reconstructed. The SAM is found to have undergone a progressive shift towards its positive phase since the fifteenth century, causing cooling of the main Antarctic continent at the same time that the Antarctic Peninsula has warmed. The positive trend in the SAM since ~AD 1940 is reproduced by multi-model climate simulations forced with rising greenhouse gas levels and later ozone depletion, and the long-term average SAM index is now at its highest level for at least the past 1,000 years. * Abram, N. J., H. V. McGregor, J. E. Tierney, M. N. Evans, N. P. McKay, D. S. Kaufman and the PAGES 2k Consortium (K. Thirumalai, B. Martrat, H. Goosse, S. J. Phipps, E. J. Steig, K. Halimeda Kilbourne, C. P. Saenger, J. Zinke, G. Leduc, J. A. Addison, P. Graham Mortyn, M.-S. Seidenkrantz, M.-A. Sicre, K. Selvaraj, H. L. Filipsson, R. Neukom, J. Gergis, M. A. J. Curran and L. von Gunten): Early onset of industrial-era warming across the oceans and continents, Nature, 536, 411-418, doi:10.1038/nature19082, 2016., 10.1038/nature19082 * Here we use post AD 1500 palaeoclimate records to show that sustained industrial-era warming of the tropical oceans first developed during the mid-nineteenth century and was nearly synchronous with Northern Hemisphere continental warming. The early onset of sustained, significant warming in palaeoclimate records and model simulations suggests that greenhouse forcing of industrial-era warming commenced as early as the mid-nineteenth century and included an enhanced equatorial ocean response mechanism. The development of Southern Hemisphere warming is delayed in reconstructions, but this apparent delay is not reproduced in climate simulations. Our findings imply that instrumental records are too short to comprehensively assess anthropogenic climate change and that, in some regions, about 180 years of industrial-era warming has already caused surface temperatures to emerge above pre-industrial values, even when taking natural variability into account. * Jungclaus, J. H., E. Bard, M. Baroni, P. Braconnot, J. Cao, L. P. Chini, T. Egorova, M. Evans, J. F. González-Rouco, H. Goosse, G. C. Hurtt, F. Joos, J. O. Kaplan, M. Khodri, K. K. Goldewijk, N. Krivova, A. N. LeGrande, S. J. Lorenz, J. Luterbacher, W. Man, A. C. Maycock, M. Meinshausen, A. Moberg, R. Muscheler, C. Nehrbass-Ahles, B. I. Otto-Bliesner, S. J. Phipps, J. Pongratz, E. Rozanov, G. A. Schmidt, H. Schmidt, W. Schmutz, A. Schurer, A. I. Shapiro, M. Sigl, J. E. Smerdon, S. K. Solanki, C. Timmreck, M. Toohey, I. G. Usoskin, S. Wagner, C.-J. Wu, K. L. Yeo, D. Zanchettin, Q. Zhang and E. Zorita: The PMIP4 contribution to CMIP6 - Part 3: The last millennium, scientific objective, and experimental design for the PMIP4 past1000 simulations, Geoscientific Model Development, 10, 4005-4033, doi:10.5194/gmd-10-4005-2017, 2017., 10.5194/gmd-10-4005-2017 * This paper describes the motivation and the experimental set-ups for the PMIP4-CMIP6 past1000 simulations, and discusses the forcing agents orbital, solar, volcanic, and land use/land cover changes, and variations in greenhouse gas concentrations. * PAGES Hydro2k Consortium (J. E. Smerdon, J. Luterbacher, S. J. Phipps, K. J. Anchukaitis, T. Ault, S. Coats, K. M. Cobb, B. I. Cook, C. Colose, T. Felis, A. Gallant, J. H. Jungclaus, B. Konecky, A. LeGrande, S. Lewis, A. S. Lopatka, W. Man, J. S. Mankin, J. T. Maxwell, B. L. Otto-Bliesner, J. W. Partin, D. Singh, N. J. Steiger, S. Stevenson, J. E. Tierney, D. Zanchettin, H. Zhang, A. R. Atwood, L. Andreu-Hayles, S. H. Baek, B. Buckley, E. R. Cook, R. D'Arrigo, S. G. Dee, M. L. Griffiths, C. Kulkarni, Y. Kushnir, F. Lehner, C. Leland, H. W. Linderholm, A. Okazaki, J. Palmer, E. Piovano, C. C. Raible, M. P. Rao, J. Scheff, G. A. Schmidt, R. Seager, M. Widmann, A. P. Williams and E. Xoplaki): Comparing proxy and model estimates of hydroclimate variability and change over the Common Era, Climate of the Past, 13, 1851-1900, doi:10.5194/cp-13-1851-2017, 2017., 10.5194/cp-13-1851-2017 * We review the principal proxy data available for hydroclimatic reconstructionsover the Common Era (CE) and highlight the contemporary understanding of how these proxies are interpreted as hydroclimate indicators. We also review the available last-millennium simulations from fully coupled climate models and discuss several outstanding challenges associated with simulating hydroclimate variability and change over the CE. * Kageyama, M., P. Braconnot, S. P. Harrison, A. M. Haywood, J. H. Jungclaus, B. L. Otto-Bliesner, J.-Y. Peterschmitt, A. Abe-Ouchi, S. Albani, P. J. Bartlein, C. Brierley, M. Crucifix, A. Dolan, L. Fernandez-Donado, H. Fischer, P. O. Hopcroft, R. F. Ivanovic, F. Lambert, D. J. Lunt, N. M. Mahowald, W. R. Peltier, S. J. Phipps, D. M. Roche, G. A. Schmidt, L. Tarasov, P. J. Valdes, Q. Zhang and T. Zhou: The PMIP4 contribution to CMIP6 - Part 1: Overview and over-arching analysis plan, Geoscientific Model Development, 11, 1033-1057, doi:10.5194/gmd-11-1033-2018, 2018., 10.5194/gmd-11-1033-2018 * Simulations of five different periods have been designed to address the objectives of the sixth phase of the Coupled Model Intercomparison Project (CMIP6): the millennium prior to the industrial epoch (CMIP6 name: past1000); the mid-Holocene, 6000 years ago (midHolocene); the Last Glacial Maximum, 21 000 years ago (lgm); the Last Interglacial, 127 000 years ago (lig127k); and the mid-Pliocene Warm Period, 3.2 million years ago (midPliocene-eoi400). This paper describes the motivation for the choice of these periods and the design of the numerical experiments and database requests, with a focus on their novel features compared to the experiments performed in previous phases of PMIP and CMIP. It also outlines the analysis plan that takes advantage of the comparisons of the results across periods and across CMIP6 in collaboration with other MIPs. * Emile-Geay, J., Cobb, K.M., Carré, M., Braconnot, P., Leloup, J., Zhou, Y., Harrison, S.P., Corrège, T., Collins, M., Driscoll, R., Elliot, M., McGregor, H.V., Schneider, B., Tudhope, A., 2015. Linkages between tropical Pacific seasonal, interannual and orbital variability during the Holocene. Nature Geoscience 9: 168-173. doi:10.1038/ngeo2608, doi:10.1038/ngeo2608 * Shows that ENSO variance was reduced throughout most of the Holocene and that this quiescence is not obvioulsy related to orbital forcing. Climate models are unable to reproduce these observations. * Albani S., Balkanski Y., Mahowald N., Winckler G., Maggi V., Delmonte B.: Aerosol-climate interactions during the Last Glacial Maximum. Curr. Clim. Change Rep., 4, 99-114, doi:10.1007/s40641-018-0100-7, 2018., 10.1007/s40641-018-0100-7 * Recent invited review on aerosol-climate interaction during the LGM * Lambert, F., J.-S. Kug, R. J. Park, N. Mahowald, G. Winckler, A. Abe-Ouchi, R. O'ishi, T. Takemura, and J.-H. Lee (2013), The role of mineral-dust aerosols in polar temperature amplification, Nat. Clim. Chang., 3(5), 487-491, doi:10.1038/nclimate1785, 10.1038/nclimate1785 * Shows the polar amplification and potential radiative forcing effect of mineral dust aerosols. * Sánchez Goñi, M.F., Desprat, S., Daniau, A.-L., Bassinot, F., Polanco-Martinez, J.M., Harrison, S.P. and ACER contributors (2017). The ACER pollen and charcoal database : a global resource to document vegetation and fire response to abrupt climate changes during the last glacial period. Earth System Science Data, 9, 679-695., https://doi.org/10.5194/essd-9-679-2017 * This global vegetation and fire data compilation shows the regional response to rapid past climate changes comparable in velocity and magnitude to those expected in the 21st-century. * Albani S., Mahowald N.: Paleodust insights onto dust impacts on climate. J. Clim., DOI: 10.1175/JCLI-D-18-0742.1, in press., 10.1175/JCLI-D-18-0742.1 * Direct impacts of dust on radiation and surface climate, including on the West African monsoon, in different climates. Because dust both scatters and absorbs SW and LW radiation, dust DRE can be both positive or negative depending on the geographical location (therefore a global budget will tend to hide the magnitude of impacts of opposing sign); we propose to use the global average of the module of DRE as a more informative metric when specifically discussing dust impacts. ===== Chapter 7: The Earth's Energy Budget, Climate Feedbacks, and Climate Sensitivity ===== Number of selected references: **54** * Braconnot, P., and M. Kageyama (2015), Shortwave forcing and feedbacks in Last Glacial Maximum and Mid-Holocene PMIP3 simulations, Phil. Trans. R. Soc. A, 373(2054), pii: 20140424., https://doi.org/10.1098/rsta.2014.0424 * climate sentivity and analogy between LGM and Holocene on snow and cloud feedbacks; végétation feedback and african monsoon, model biases and african monsoon * de Boer, Bas, Haywood, Alan M., Dolan, Aisling M., Hunter, Stephen J., and Prescott, Caroline L., 2017. The Transient Response of Ice Volume to Orbital Forcing During the Warm Late Pliocene, Geophysical Research Letters, 44, 10,486--10,494., https://doi.org/10.1002/2017GL073535 * The paper presents transient ice sheet predictions forced by multiple climate snapshots derived from HadCM3 set up with late Pliocene boundary conditions, forced with different orbital forcing scenarios. The results indicate that insolation forcing between the hemispheres was out of phase during MIS K1 and led to an asynchronous response of ice volume globally. * Langebroek, P. M. and Nisancioglu, K. H., 2014: Simulating last interglacial climate with NorESM: role of insolation and greenhouse gases in the timing of peak warmth, Clim. Past, 10, 1305-1318. , https://doi.org/10.5194/cp-10-1305-2014 * It shows the difference in impact of insolation versus greenhouse gas forcing on the (timing of peak) warmth during the last interglacial. Global simulations using the Norwegian Earth System Model, with a focus on explaining proxy records in the North Atlantic. * Otto-Bliesner, B.L. et al., 2017: The PMIP4 contribution to CMIP6 - Part 2: Two interglacials, Scientific objectives and experimental design of the PMIP4-CMIP6 Holocene and Last Interglacial simulations. Geoscientific Model Development, 10, 3979-4003, https://doi.org/10.5194/gmd-10-3979-2017 * This paper describes the protocols for the mid-Holocene (6 ka) and Last Interglacial (127 ka) Tier 1 simulations, as well as numerous Tier 2 simulations to assess the sensitivities to prescribed vegetation, ice sheets, freshwater fluxes, and alternative states of orbital forcing. For the first time, the LIG is included for CMIP6 and PMIP4, allowing a multi-model assessment of this important period for testing our knowledge of climate-ice sheet interactions in warm climates. * Fasullo, J.T., R. Tomas, S. Stevenson, B. Otto-Bliesner, E. Brady, E. Wahl, 2017: The amplifying influence of increased ocean stratification on a future year without a summer, Nature Communications, 8, 1236. doi:10.1038/s41467-017-01302-z, https://doi.org/10.1038/s41467-017-01302-z * CESM simulations of both the 1815 Tambora eruption and a hypothetical analogous future eruption are compared, the latter occurring in 2085 assuming a business-as-usual climate scenario. The 1815 eruption drove strong responses in both the ocean and cryosphere that were fundamental to driving the Year-Without-A-Summer. Through modulation of ocean stratification and near-surface winds, global warming contributes to an amplified surface climate response in CESM. * Ohgaito, R., Abe-Ouchi, A., O'ishi, R., Takemura, T., Ito, A., Hajima, T., Watanabe, S., and Kawamiya, M.: Effect of high dust amount on surface temperature during the Last Glacial Maximum: a modelling study using MIROC-ESM, Clim. Past, 14, 1565-1581, https://doi.org/10.5194/cp-14-1565-2018, 2018, https://doi.org/10.5194/cp-14-1565-2018 * Effect of aerosols on climate is major uncertainty for future projection.This paper discusses how the glaciogenic dust can affect the LGMclimate. A possibility of less cooling by high dust load surroundingof Antarctica is suggested. * Zanchettin, D., Khodri, M., Timmreck, C., Toohey, M., Schmidt, A., Gerber, E. P., Hegerl, G., Robock, A., Pausata, F. S. R., Ball, W. T., Bauer, S. E., Bekki, S., Dhomse, S. S., LeGrande, A. N., Mann, G. W., Marshall, L., Mills, M., Marchand, M., Niemeier, U., Poulain, V., Rozanov, E., Rubino, A., Stenke, A., Tsigaridis, K., and Tummon, F.: The Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP): experimental design and forcing input data for CMIP6, Geosci. Model Dev., 9, 2701-2719, doi:10.5194/gmd-9-2701-2016, 2016, 10.5194/gmd-9-2701-2016, 2016 * This paper presents the experimental design of the "Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP), which includes idealized experiments focused on the short-term atmospheric as well as long-term coupled response to volcanic forcing. The core idea of VolMIP is to constrain radiative forcing among the participating models to focus on the climatic response, hence reference forcing dataare provided in terms of optical aerosol properties for a series of reference eruptions. * Zanchettin, D., O. Bothe, H. F. Graf, S. J. Lorenz, J. Luterbacher, C. Timmreck, and J. H. Jungclaus (2013) Background conditions influence the decadal climate response to strong volcanic eruptions. J. Geophys. Res. Atm., 118(10): 4090-4106, doi:10.1002/jgrd.50229, 10.1002/jgrd.50229 * This study illustrates how the decadal climate response to strong volcanic eruptions depends on the background climate state at the time of the eruption and on the presence and magnitude of additional external forcings acting at the same time. It demonstrates that background climate conditions are not merely a source of additive noise for post-eruption decadal climate variability but actively influence the mechanisms involved in the post-eruption decadal evolution. * Khodri M., Izumo T., Vialard J., Janicot S., Cassou C., Lengaigne M., Mignot J., Gastineau G., E. Guilyardi, Lebas N., Robock A. and M.J McPhaden, Tropical explosive volcanic eruptions can trigger El Niño by cooling tropical Africa, Nature Communications, 8, 778 (2017). , 10.1038/s41467-017-00755-6 * This paper presents new evidences for a possible interference of volcanic forcing from tropical stratospheric eruptions on ENSO cycle and discusses the underlying physical processes. Targeted climate model simulations emphasize that Pinatubo-like eruptions tend to shorten La Niñas, lengthen El Niños and induce anomalous warming when occurring during neutral states. It also presents a new mechanisms suggesting that volcanically induced cooling in tropical Africa weakens the West African monsoon, and the resulting atmospheric Kelvin wave can drive equatorial westerly wind anomalies over the western Pacific. This wind anomaly is further amplified by air-sea interactions in the Pacific, favouring an El Niño-like response. * Stoffel M, Khodri M., Corona C., Guillet S., Poulain V., Bekki S., Guiot J., Luckman B.H., Oppenheimer C., Lebas N., Beniston M.& Masson-Delmotte V., Reconciling reconstructions and simulations of volcanic cooling, Nature Geoscience, 8, 784-788 (2015), 10.1038/NGEO2526, 2015 * The climatic impact of the largest volcanic events has been assessed in numerous modelling studies and tree-ring-based hemispheric temperature reconstructions. However, volcanic surface cooling derived from PMIP3 climate model simulations is systematically much stronger than the cooling seen in tree-ring-based proxies, suggesting that the proxies underestimate cooling; and/or the modelled forcing is unrealistically high. This paper present a new summer temperature reconstructions for the Northern Hemisphere from tree-ring width and maximum latewood density over the past 1,500 years in comparison to simulated climate effects of two large eruptions, in AD 1257 and 1815, using a climate model that accounts explicitly for self-limiting aerosol microphysical processes. Results reveal for the first time an agreement between modelled and tree-ring based reconstruction of mean Northern Hemisphere extra-tropical summer cooling over land estimated between 0.8 to 1.3 degC for these eruptions. This reconciliation of proxy and model evidence paves the way to improved assessment of the role of both past and future volcanism in climate forcing. * Schenk F., Väliranta M., Muschitiello F., Tarasov L., Heikkilä M., Björck S., Brandefelt J., Johansson A.V., Näslund J.O., Wohlfarth B. (2018): Warm summers during the Younger Dryas cold reversal. Nat. Communications 9:1634, https://doi.org/10.1038/s41467-018-04071-5 * Very cold North Atlantic Ocean states in response to a weak AMOC cause persistent atmospheric blocking over Europe during summer. Proxy-model evidence suggests warmer and very dry conditions in response to a slowdown of the AMOC consistent with observations since the 1980s. * García-García A., Cuesta-Valero F.J., Beltrami H. and Smerdon J.E. (2016). Simulation of air and ground temperatures in PMIP3/CMIP5 last millennium simulations: implications for climate reconstructions from borehole temperature profiles. Environmental Research Letter, 11(4):044022., https://doi.org/10.1088/1748-9326/11/4/044022 * This paper tests the methodology employed to reconstruct past ground surface temperature histories from borehole temperature profiles using simulations from the PMIP3/CMIP5 archives. * Cuesta-Valero F.J., García-García A., Beltrami H. and Smerdon J.E. (2016). First Assessment of Continental Energy Storage in CMIP5 Simulations. Geophysical Research Letters, 43., https://doi.org/10.1002/2016GL068496 * This paper assesses the ability of 30 CMIP5 models to reproduce the change in heat storage within the continental subsurface for the second half of the 20th century against estimates from borehole temperature profiles. * Cuesta-Valero, F. J., García-García, A., Beltrami, H., Zorita, E., and Jaume-Santero, F.: Long-term Surface Temperature (LoST) Database as a complement for GCM preindustrial simulations, Clim. Past Discuss., 2018., https://doi.org/10.5194/cp-2018-133 * A database containing long-term preindustrial absolute surface temperatures over North America is assembled and freely released for the use of the community. The long-term surface temperatures described here are estimated from geothermal data. These temperatures are useful for studying the stability of permafrost soils, as well as for evaluating the simulated preindustrial climatology, which may improve the estimated equilibrium climate sensitivity from climate models. * Luterbacher, J. and coauthors, 2016: European summer temperatures since Roman times. Environmental Research Letters, 11, 024001, doi:10.1088/1748-9326/11/2/024001 * A comparison with an ensemble of climate model simulations (PMIP5/CMIP3) suggests that the reconstructed European summer temperature variability over the period 850-2000CE reflects changes in both internal variability and external forcing on multi-decadal time-scales. * K. L. Yeo, N. A. Krivova, S. K. Solanki. EMPIRE: A robust empirical reconstruction of solar irradiance variability. J. Geophys. Res. (Space Phys.) 122, 3888-3914, 2017., 10.1002/2016JA023733 * The paper resolved the long-standing controversy over why proxy and physics-based models of solar irradiance variability disagree in the UV, confirming that the variability in the UV is higher than believed, which is critical for ozone balance. * 8. K. L. Yeo, W. T. Ball, N. A. Krivova, S. K. Solanki, Y. C. Unruh, J. Morrill. UV solar irradiance in observations and the NRLSSI and SATIRE-S models. J. Geophys. Res. (Space Phys.) 120, 6055-6070, 2015., 10.1002/2015JA021277 * The paper tackled the long-standing controversy over why proxy and physics-based models of solar irradiance variability disagree in the UV, which is critical for ozone balance. * Loomis, S.E., Russell, J.M., Verschuren, D., Morrill, C., De Cort, G., Sinninghe Damste, J.S., Olago, D., Eggermont, H., Street-Perrott, F.A., Kelly, M.A. 2017. The tropical lapse rate steepened during the Last Glacial Maximum. Science Advances 3: e1600815., 10.1126/sciadv.1600815 * A new 25,000-year temperature reconstruction from Mount Kenya, East Africa, demonstrates that cooling during the Last Glacial Maximum was amplified with elevation. Comparison of our data with PMIP3 LGM simulations indicates that state-of-the-art models underestimate this lapse-rate change. * Hargreaves, J. C., & Annan, J. D. (2016). Could the Pliocene constrain the equilibrium climate sensitivity? Climate of the Past, 12(8), 1591-1599. , http://doi.org/10.5194/cp-12-1591-2016 * The mid-Pliocene Warm Period (mPWP) is the most recent interval in which atmospheric carbon dioxide was substantially higher than in modern pre-industrial times. Here we analyse results from the PlioMIP and, for the first time, discuss the potential for this interval to usefully constrain the equilibrium climate sensitivity. * Annan, J. D., & Hargreaves, J. C. (2015). A perspective on model-data surface temperature comparison at the Last Glacial Maximum. Quaternary Science Reviews, 107, 1-10. , http://doi.org/10.1016/j.quascirev.2014.09.019 * We review progress in model and proxy-based reconstruction of the surface temperature field of the Last Glacial Maximum. The magnitudes of the large-scale changes are increasingly well-constrained, with a recent model-data synthesis generating a value of 4 C, which suggests a moderate equilibrium climate sensitivity of about 2.5 C. * Harrison, S. P., Bartlein, P. J., Izumi, K., Li, G., Annan, J., Hargreaves, J., et al. (2015). Evaluation of CMIP5 palaeo-simulations to improve climate projections. Nature Climate Change, 5(8), 735-743. , http://doi.org/10.1038/nclimate2649 * Past climate changes provide a unique opportunity for out-of-sample evaluation of model performance. Palaeo-evaluation has shown that the large-scale changes seen in twenty-first-century projections, including enhanced land-sea temperature contrast, latitudinal amplification, changes in temperature seasonality and scaling of precipitation with temperature, are likely to be realistic. * Schmidt, G. A., Annan, J. D., Bartlein, P. J., Cook, B. I., Guilyardi, E., Hargreaves, J. C., et al. (2014). Using palaeo-climate comparisons to constrain future projections in CMIP5. Climate of the Past, 10(1), 221-250. , http://doi.org/10.5194/cp-10-221-2014 * Using palaeo-climate comparisons to constrain future projections! * Marzin, C., Braconnot, P. and Kageyama, M. (2013). Relative impacts of insolation changes, meltwater fluxes and ice sheets on African and Asian monsoons during the Holocene. Climate Dynamics. 41: 2267-2286., https://doi.org/10.1007/s00382-013-1948-9 * This paper analyse the teleconnection between the remnant northern hemisphere ice-sheet in the early Holocene and fresh water fluxes induced by ice sheet melting on the African and Indian monsoons. It shows that despite similarities in the response to these two factors in the Atlantic the teleconnections are different, mainly because of differences in the way the thermohaline circulation is affected. * Luan, Y. H., et al. (2015). "Tropical Pacific mean state and ENSO changes: sensitivity to freshwater flux and remnant ice sheets at 9.5 ka BP." Climate Dynamics 44(3-4): 661-678., https://doi.org/10.1007/s00382-015-2467-7 * Using as a reference a simulation of the early Holocene, the present study explores the relative contribution of ice-sheet and fresh water fluxes on themean climate state and ENSO variability in the tropical Pacific.The freshwater flux impact on ocean circulation and atmospheric feedbacks enhances ENSO amplitude. A feedback analysis suggests that it is due to the wind-thermocline feedback. The remnant ice sheett does not induce significant change in ENSO. Itexhibits a slight SST variability increase at the east coast and a reduction in the middle of the basin driven by the net. The freshwater flux forcing strengthens the amplitude of EP El Niño events. This mansucripts halp thus to unerstand the diversity of EL Niño event and the response of El Niño to external forcings. * Saint-Lu, M., P. Braconnot, J. Leloup, and O. Marti (2016), The role of El Niño in the global energy redistribution: a case study in the mid-Holocene, Climate Dynamics, 1-18., n/a * This manuscript investigate the linkages between El Niño charachteristics and the mean climate, using an energy framework. It shows that the role of global energy pump played by the tropical Pacific is reduced in the mid-Holocene in simulation with the IPSL model, both in long-term mean and during El Niño years. We demonstrate that this is not only a direct response toinsolation forcing but this is further amplified by changes in internal processes. This work gives a new approach to address El Niño changes, from the perspective of the role of El Niño in global energy redistribution. * Lu, Z., & Liu, Z. (2018). Orbital modulation of ENSO seasonal phase locking. Climate Dynamics., https://doi.org/10.1007/s00382-018-4382-1 * This paper shows the mechanisms how the timing of El Nino-Southern Oscillation peaks was modulated by orbital forcing, and calls for further investigation in CMIP6 ensembles for the future change of this phenomenon. * Lunt, D. J., A. Abe-Ouchi, P. Bakker, A. Berger, P. Braconnot, S. Charbit, N. Fischer, N. Herold, J. H. Jungclaus, V. C. Khon, U. Krebs-Kanzow, P. M. Langebroek, G. Lohmann, K. H. Nisancioglu, B. Otto-Bliesner, W. Park, M. Pfeiffer, S. J. Phipps, M. Prange, R. Rachmayani, H. Renssen, N. Rosenbloom, B. Schneider, E. J. Stone, K. Takahashi, W. Wei, Q. Yin and Z. S. Zhang: A multi-model assessment of last interglacial temperatures, Climate of the Past, 9, 699-717, doi:10.5194/cp-9-699-2013, 2013., 10.5194/cp-9-699-2013 * Examines the PMIP3 simulations of the Last Interglacial and finds that the models do not agree well with reconstructions. In particular, the models fail to replicate the reconstructed warming at high latitudes. * Schurer, A. P., G. C. Hegerl, M. E. Mann, S. F. B. Tett and S. J. Phipps: Separating Forced from Chaotic Climate Variability over the Past Millennium, Journal of Climate, 26, 6954-6973, doi:10.1175/JCLI-D-12-00826.1, 2013., 10.1175/JCLI-D-12-00826.1 * External forcings are found to contribute significantly towards long-term temperature variations over the last millennium, particularly from 1400 CE onwards. It is found that the recent observed 50- and 100-yr hemispheric temperature trends are substantially larger than estimates of the amplitude of internal climate variability. * Abram, N. J., R. Mulvaney, F. Vimeux, S. J. Phipps, J. Turner and M. H. England: Evolution of the Southern Annular Mode during the past millennium, Nature Climate Change, 4, 564-569, doi:10.1038/NCLIMATE2235, 2014., 10.1038/NCLIMATE2235 * Changes in the Southern Annular Mode over the last millennium are reconstructed. The SAM is found to have undergone a progressive shift towards its positive phase since the fifteenth century, causing cooling of the main Antarctic continent at the same time that the Antarctic Peninsula has warmed. The positive trend in the SAM since ~AD 1940 is reproduced by multi-model climate simulations forced with rising greenhouse gas levels and later ozone depletion, and the long-term average SAM index is now at its highest level for at least the past 1,000 years. * Bakker, P., V. Masson-Delmotte, B. Martrat, S. Charbit, H. Renssen, M. Gröger, U. Krebs-Kanzow, G. Lohman, D. J. Lunt, M. Pfeiffer, S. J. Phipps, M. Prange, S. P. Ritz, M. Schulz, B. Stenni, E. J. Stone and V. Varma: Temperature trends during the Present and Last Interglacial periods - a multi-model-data comparison, Quaternary Science Reviews, 99, 224-243, doi:10.1016/j.quascirev.2014.06.031, 2014., 10.1016/j.quascirev.2014.06.031 * The reconstructed Present Interglacial (PIG) and Last Interglacial (LIG) Northern Hemisphere mid-to-high latitude cooling compares well with multi-model, mean temperature trends for the warmest months and that these cooling trends reflect a linear response to the warmest-month insolation decrease over the interglacial intervals. The most notable exception is the strong LIG cooling trend reconstructed from Greenland ice cores that is not simulated by any of the models. A striking model-data mismatch is found for both the PIG and the LIG over large parts of the mid-to-high latitudes of the Southern Hemisphere where the data depicts negative temperature trends that are not in agreement with near zero trends in the simulations. * McGregor, H. V., M. N. Evans, H. Goosse, G. Leduc, B. Martrat, J. A. Addison, P. G. Mortyn, D. W. Oppo, M.-S. Seidenkrantz, M.-A. Sicre, S. J. Phipps, K. Selveraj, K. Thirumalai, H. L. Filipsson and V. Ersek: Robust global ocean cooling trend for the pre-industrial Common Era, Nature Geoscience, 8, 671-677, doi:10.1038/NGEO2510, 2015., 10.1038/NGEO2510 * Here we present a global synthesis of sea surface temperatures for the Common Era (CE) derived from 57 individual marine reconstructions that meet strict quality control criteria. We observe a cooling trend from 1 to 1800 CE that is robust against explicit tests for potential biases in the reconstructions. Climate simulations using single and cumulative forcings suggest that the ocean surface cooling trend from 801 to 1800 CE is not primarily a response to orbital forcing but arises from a high frequency of explosive volcanism. Our results show that repeated clusters of volcanic eruptions can induce a net negative radiative forcing that results in a centennial and global scale cooling trend via a decline in mixed-layer oceanic heat content. * Abram, N. J., H. V. McGregor, J. E. Tierney, M. N. Evans, N. P. McKay, D. S. Kaufman and the PAGES 2k Consortium (K. Thirumalai, B. Martrat, H. Goosse, S. J. Phipps, E. J. Steig, K. Halimeda Kilbourne, C. P. Saenger, J. Zinke, G. Leduc, J. A. Addison, P. Graham Mortyn, M.-S. Seidenkrantz, M.-A. Sicre, K. Selvaraj, H. L. Filipsson, R. Neukom, J. Gergis, M. A. J. Curran and L. von Gunten): Early onset of industrial-era warming across the oceans and continents, Nature, 536, 411-418, doi:10.1038/nature19082, 2016., 10.1038/nature19082 * Here we use post AD 1500 palaeoclimate records to show that sustained industrial-era warming of the tropical oceans first developed during the mid-nineteenth century and was nearly synchronous with Northern Hemisphere continental warming. The early onset of sustained, significant warming in palaeoclimate records and model simulations suggests that greenhouse forcing of industrial-era warming commenced as early as the mid-nineteenth century and included an enhanced equatorial ocean response mechanism. The development of Southern Hemisphere warming is delayed in reconstructions, but this apparent delay is not reproduced in climate simulations. Our findings imply that instrumental records are too short to comprehensively assess anthropogenic climate change and that, in some regions, about 180 years of industrial-era warming has already caused surface temperatures to emerge above pre-industrial values, even when taking natural variability into account. * Jungclaus, J. H., E. Bard, M. Baroni, P. Braconnot, J. Cao, L. P. Chini, T. Egorova, M. Evans, J. F. González-Rouco, H. Goosse, G. C. Hurtt, F. Joos, J. O. Kaplan, M. Khodri, K. K. Goldewijk, N. Krivova, A. N. LeGrande, S. J. Lorenz, J. Luterbacher, W. Man, A. C. Maycock, M. Meinshausen, A. Moberg, R. Muscheler, C. Nehrbass-Ahles, B. I. Otto-Bliesner, S. J. Phipps, J. Pongratz, E. Rozanov, G. A. Schmidt, H. Schmidt, W. Schmutz, A. Schurer, A. I. Shapiro, M. Sigl, J. E. Smerdon, S. K. Solanki, C. Timmreck, M. Toohey, I. G. Usoskin, S. Wagner, C.-J. Wu, K. L. Yeo, D. Zanchettin, Q. Zhang and E. Zorita: The PMIP4 contribution to CMIP6 - Part 3: The last millennium, scientific objective, and experimental design for the PMIP4 past1000 simulations, Geoscientific Model Development, 10, 4005-4033, doi:10.5194/gmd-10-4005-2017, 2017., 10.5194/gmd-10-4005-2017 * This paper describes the motivation and the experimental set-ups for the PMIP4-CMIP6 past1000 simulations, and discusses the forcing agents orbital, solar, volcanic, and land use/land cover changes, and variations in greenhouse gas concentrations. * Ackerley, D., J. Reeves, C. Barr, H. Bostock, K. Fitzsimmons, M.-S. Fletcher, C. Gouramanis, H. McGregor, S. Mooney, S. J. Phipps, J. Tibby and J. Tyler: Evaluation of PMIP2 and PMIP3 simulations of mid-Holocene climate in the Indo-Pacific, Australasian and Southern Ocean regions, Climate of the Past, 13, 1661-1684, doi:10.5194/cp-13-1661-2017, 2017., 10.5194/cp-13-1661-2017 * Shows that the PMIP2/PMIP3 models and proxies agree on the differences in climate state for 6 ka relative to 0 ka, when they are insolation driven. The largest uncertainty between the models and the proxies occurs over the Indo-Pacific Warm Pool (IPWP). * PAGES Hydro2k Consortium (J. E. Smerdon, J. Luterbacher, S. J. Phipps, K. J. Anchukaitis, T. Ault, S. Coats, K. M. Cobb, B. I. Cook, C. Colose, T. Felis, A. Gallant, J. H. Jungclaus, B. Konecky, A. LeGrande, S. Lewis, A. S. Lopatka, W. Man, J. S. Mankin, J. T. Maxwell, B. L. Otto-Bliesner, J. W. Partin, D. Singh, N. J. Steiger, S. Stevenson, J. E. Tierney, D. Zanchettin, H. Zhang, A. R. Atwood, L. Andreu-Hayles, S. H. Baek, B. Buckley, E. R. Cook, R. D'Arrigo, S. G. Dee, M. L. Griffiths, C. Kulkarni, Y. Kushnir, F. Lehner, C. Leland, H. W. Linderholm, A. Okazaki, J. Palmer, E. Piovano, C. C. Raible, M. P. Rao, J. Scheff, G. A. Schmidt, R. Seager, M. Widmann, A. P. Williams and E. Xoplaki): Comparing proxy and model estimates of hydroclimate variability and change over the Common Era, Climate of the Past, 13, 1851-1900, doi:10.5194/cp-13-1851-2017, 2017., 10.5194/cp-13-1851-2017 * We review the principal proxy data available for hydroclimatic reconstructionsover the Common Era (CE) and highlight the contemporary understanding of how these proxies are interpreted as hydroclimate indicators. We also review the available last-millennium simulations from fully coupled climate models and discuss several outstanding challenges associated with simulating hydroclimate variability and change over the CE. * Kageyama, M., P. Braconnot, S. P. Harrison, A. M. Haywood, J. H. Jungclaus, B. L. Otto-Bliesner, J.-Y. Peterschmitt, A. Abe-Ouchi, S. Albani, P. J. Bartlein, C. Brierley, M. Crucifix, A. Dolan, L. Fernandez-Donado, H. Fischer, P. O. Hopcroft, R. F. Ivanovic, F. Lambert, D. J. Lunt, N. M. Mahowald, W. R. Peltier, S. J. Phipps, D. M. Roche, G. A. Schmidt, L. Tarasov, P. J. Valdes, Q. Zhang and T. Zhou: The PMIP4 contribution to CMIP6 - Part 1: Overview and over-arching analysis plan, Geoscientific Model Development, 11, 1033-1057, doi:10.5194/gmd-11-1033-2018, 2018., 10.5194/gmd-11-1033-2018 * Simulations of five different periods have been designed to address the objectives of the sixth phase of the Coupled Model Intercomparison Project (CMIP6): the millennium prior to the industrial epoch (CMIP6 name: past1000); the mid-Holocene, 6000 years ago (midHolocene); the Last Glacial Maximum, 21 000 years ago (lgm); the Last Interglacial, 127 000 years ago (lig127k); and the mid-Pliocene Warm Period, 3.2 million years ago (midPliocene-eoi400). This paper describes the motivation for the choice of these periods and the design of the numerical experiments and database requests, with a focus on their novel features compared to the experiments performed in previous phases of PMIP and CMIP. It also outlines the analysis plan that takes advantage of the comparisons of the results across periods and across CMIP6 in collaboration with other MIPs. * Goelzer, H., Huybrechts, P., Loutre, M. F., and Fichefet, T.: Impact of ice sheet meltwater fluxes on the climate evolution at the onset of the Last Interglacial, Clim. Past, 12, 1721-1737, doi:10.5194/cp-12-1721-2016, 2016., https://doi.org/10.5194/cp-12-1721-2016 * This paper shows modelling evidence that freshwater fluxes from the ice sheets are an important driver for climate changes at the onset of the Last Interglacial. * Goelzer, H., Huybrechts, P., Loutre, M. F., and Fichefet, T.: Last Interglacial climate and sea-level evolution from a coupled ice sheet-climate model, Clim. Past, 12, 2195-2213, doi:10.5194/cp-12-2195-2016, 2016., https://doi.org/10.5194/cp-12-2195-2016 * The paper describes one of the first attempts of a fully coupled transient climate-ice sheet simulation of the Last Interglacial period. The results suggest that the relative timing of sea-level contributions from the Greenland and Antarctic ice sheets are important for the interpretation of paleo sea-level records from that period. * Bartlein, P.J., S.P. Harrison and K. Izumi, 2017, Underlying causes of Eurasian mid-continental aridity in simulations of mid-Holocene climate, Geophysical Research Letters. 44:1-9, http://dx.doi.org/10.1002/2017GL074476 * Discusses a long-standing mismatch between climate-model simulations and paleo observations and relates these to present-day biases in atmospheric circulation and moisture flux * Izumi, K. and P.J. Bartlein, 2016, North American paleoclimate reconstructions for the last glacial maximum using an inverse-modeling through iterative-forward-modeling (IMIFM) approach applied to pollen data. Geophysical Research Letters. 43:1-8, http://dx.doi.org/10.1002/2016GL070152 * Describes a method for interative forward-modeling reconstructions of paleoclimates * Harrison, S.P., P.J. Bartlein & I.C. Prentice, 2016, What have we learnt from palaeoclimate simulations? Journal of Quaternary Science31:363-385, https://doi.org/10.1002/jqs.2842 * Overview of results from comparisons of climate-model simulations and paleoclimatic data syntheses * Izumi, K., Bartlein, P.J., Harrison, S.P., 2015. Energy-balance mechanisms underlying consistent large-scale temperature responses in warm and cold climates. Climate Dynamics. 44:3111-3127., https://doi.org/10.1007/s00382-014-2189-2 * Explains the energy-balance sources of the large-scale temperature responses in warm and cold climates * Harrison, S.P., Bartlein, P.J., Brewer, S., Prentice, I.C., Boyd, M., Hessler, I., Holmgren, K., Izumi, K., Willis, K., 2014. Climate model benchmarking with glacial and mid-Holocene climates. Climate Dynamics 43, 671-688., https://doi.org/10.1007/s00382-013-1922-6 * Systematic benchmarking of the PMIP3 models * Martin Calvo, M., Prentice, I.C., Harrison, S.P., 2014. Climate versus carbon dioxide controls on biomass burning: a model analysis of the glacial-interglacial contrast. Biogeosciences, 11, 6017-6027. doi:10.5194/bg-11-6017-2014, doi:10.5194/bg-11-6017-2014a * Demonstrates that changing CO2 since the Last Glacial Maximum has affected fire regimes through altering productivity and hence fuel loads. By analogy, both rising CO2 and climate must be considered as risk factors for wildfire. * Izumi, K., P.J. Bartlein and S.P. Harrison, 2013, Consistent large-scale temperature responses in warm and cold climates, Geophysical Research Letters, https://dow.org/10.1002/grl.50350 * Demonstrates that there are consistent large-scale temperature responses in warm and cold climates using paleo simulations and reconstructions along with future simulations * Prado, L. F., Wainer, I., Chiessi, C. M. (2013). Mid-Holocene PMIP3/CMIP5 model results: Intercomparison for the South American Monsoon System. The Holocene, Vol 23, Issue 12, 1915-1920., 10.1177/0959683613505336 * This paper contains an unpdated proxy compilation for South American Monsoon System during the Mid-Holocene, and also a data-model comparison using the PMIP3 models. * Goelzer, H., Huybrechts, P., Loutre, M. F., and Fichefet, T.: Impact of ice sheet meltwater fluxes on the climate evolution at the onset of the Last Interglacial, Clim. Past, 12, 1721-1737, doi:10.5194/cp-12-1721-2016, 2016., 10.5194/cp-12-1721-2016 * Paper highlights the important role of freshwater fluxes for the climate, ice sheet and sea-level evolution at the onset of the last Interglacial. * Albani S., Balkanski Y., Mahowald N., Winckler G., Maggi V., Delmonte B.: Aerosol-climate interactions during the Last Glacial Maximum. Curr. Clim. Change Rep., 4, 99-114, doi:10.1007/s40641-018-0100-7, 2018., 10.1007/s40641-018-0100-7 * Recent invited review on aerosol-climate interaction during the LGM * Chandan and Peltier 2018: On the mechanisms of warming the mid-Pliocene and the inference of a hierarchy of climate sensitivities with relevance to the understanding of climate futures. Climate of the past, 14, 825-856, https://doi.org/10.5194/cp-14-825-2018 * This paper derives a hierarchy of climate sensitivities, applicable on various timescales, from modelling studies of the future-like warm period of the mid-Pliocene. * Ibarra, D. E., Oster, J. L., Winnick, M. J., Caves Rugenstein, J. K., Byrne, M. P., & Chamberlain, C. P. (2018). Warm and cold wet states in the western United States during the Pliocene-Pleistocene. Geology, 46(4), 355-358., 10.1130/G39962.1 * Water cycle and regional moisture energy balance budget change constrained by geologic/paleoclimate data and PMIP models in semi-arid region. * Cuesta-Valero, F. J., García-García, A., Beltrami, H., Zorita, E., & Jaume-Santero, F. (2019). Long-term Surface Temperature (LoST) database as a complement for GCM preindustrial simulations. Climate of the Past, 15(3), 1099-1111, https://doi.org/10.5194/cp-15-1099-2019 * The paper provides with a new long-term past absolute temperature database that can help to constrain model estimates of climate sensitivity. * Yoshimori, M. and Suzuki, M.: The relevance of mid-Holocene Arctic warming to the future, Clim. Past, 15, 1375-1394, https://doi.org/10.5194/cp-15-1375-2019, 2019., 10.5194/cp-15-1375-2019 * The paper provides a physical basis of why the mid-Holocene Arctic warming information is useful for the future, i.e., paleo-constraint for the future. * Sánchez Goñi, M.F., Ferretti, P., Polanco-Martinez, J.M., Rodrigues, T., Alonso-Garcia, M., Rodriguez-Tovar, F.J., Dorador, J., Desprat, S. (2019). Pronounced northward shift of the westerlies during MIS 17 leading to the strong 100-kyr ice age cycles. Earth and Planetary Science Letters 511, 117-129., https://doi.org/10.1016/j.epsl.2019.01.032. * During MIS 17 (700 ka), a cold interglacial characterized by the lowest atmospheric CO2 concentrations of the last 800,000 years, the Iberian Peninsula was paradoxically marked by the maximum in the Mediterranean forest expansion indicating strong winter precipitation and summer warmth. These data indicate a decoupling between global and regional climates. This work also highlights the important contribution of the westerlies leading to the strong 100-kyr ice age cycles. These atmospheric changes remain, however, a key area of uncertainty in past and future climate model simulations. * Albani S., Mahowald N.: Paleodust insights onto dust impacts on climate. J. Clim., DOI: 10.1175/JCLI-D-18-0742.1, in press., 10.1175/JCLI-D-18-0742.1 * Direct impacts of dust on radiation and surface climate, including on the West African monsoon, in different climates. Because dust both scatters and absorbs SW and LW radiation, dust DRE can be both positive or negative depending on the geographical location (therefore a global budget will tend to hide the magnitude of impacts of opposing sign); we propose to use the global average of the module of DRE as a more informative metric when specifically discussing dust impacts. ===== Chapter 8: Water Cycle Changes ===== Number of selected references: **48** * Braconnot, P., and M. Kageyama (2015), Shortwave forcing and feedbacks in Last Glacial Maximum and Mid-Holocene PMIP3 simulations, Phil. Trans. R. Soc. A, 373(2054), pii: 20140424., https://doi.org/10.1098/rsta.2014.0424 * climate sentivity and analogy between LGM and Holocene on snow and cloud feedbacks; végétation feedback and african monsoon, model biases and african monsoon * Klein F., H. Goosse, D. Verschuren, N. Graham, 2016. Comparison of simulated and reconstructed variations in East African hydroclimate over the last millennium. Climate of the Past Clim. Past, 12, 1499-1518 , https://doi.org/10.5194/cp-12-1499-2016 * The paper shows the large role of natural variability in past precipitation changes in East Africa and discuss the role of Indian ocean SST. * Brierley, C., & Wainer, I. (2018). Inter-annual variability in the tropical Atlantic from the Last Glacial Maximum into future climate projections simulated by CMIP5/PMIP3. Climate of the Past, 14(10), 1377-1390., https://doi.org/10.5194/cp-14-1377-2018 * We look at changes in two climate modes (Atlantic Nino and Atlantic Meridional Mode) and how they respond to past/future forcing. Whilst there are robust changes not obvious constraints emerge across the ensemble . * Sun, Y. et al., 2016:Drivers and mechanisms for enhanced summer monsoon precipitation over East Asia during the mid-Pliocene in the IPSL-CM5A. Climate Dynamics,46,1437-1457, https://doi.org/10.1007/s00382-015-2656-4 * performing paleomonsoon dynamics is useful constraint for understanding the future monsoon behaviors * Otto-Bliesner, B.L. et al., 2017: The PMIP4 contribution to CMIP6 - Part 2: Two interglacials, Scientific objectives and experimental design of the PMIP4-CMIP6 Holocene and Last Interglacial simulations. Geoscientific Model Development, 10, 3979-4003, https://doi.org/10.5194/gmd-10-3979-2017 * This paper describes the protocols for the mid-Holocene (6 ka) and Last Interglacial (127 ka) Tier 1 simulations, as well as numerous Tier 2 simulations to assess the sensitivities to prescribed vegetation, ice sheets, freshwater fluxes, and alternative states of orbital forcing. For the first time, the LIG is included for CMIP6 and PMIP4, allowing a multi-model assessment of this important period for testing our knowledge of climate-ice sheet interactions in warm climates. * Zhu, J., Z.Y. Liu, E. Brady, B. Otto-Bliesner, J.X. Zhang, J. Nusbaumer, T.E. Wong, A. Jahn, and D. Noone, 2017: Investigating the direct meltwater effect in terrestrial oxygen-isotope paleoclimate records using an isotope-enabled Earth system model. Geophysical Research Letters, 44, 12501-12510., https://doi.org/10.1002/2017GL076253 * Variations in terrestrial oxygen-isotope reconstructions from ice cores and speleothems have been primarily attributed to climatic changes of surface air temperature, precipitation amount, or atmospheric circulation. New modeling results with the water isotope-enabled CESM suggest important nuances for past climate interpretations of delta18O. * Tabor, C., B. Otto-Bliesner, E. Brady, J. Nusbaumer, J. Zhu, M. Erb, A. Wong, Z. Liu, and D. Noone, 2018: Interpreting precession driven del18O variability in the South Asian monsoon region. JGR-Atmospheres, 123., https://doi.org/10.1029/2018JD028424 * CESM with water isotope tracers and water-tagging capability is used to deconstruct the precession signal found in South Asian Summer Monsoon delta18O speleothem records. This paper shows that changes in the relative moisture contributions from different source regions drive much of the SASM delta18O signal, with more nearby moisture sources during Northern Hemisphere summer at aphelion and more distant moisture sources during Northern Hemispheresummer at perihelion, explaining a significant portion of the long-term variability found in SASM speleothem records. * Mares, C., I. Mares, H. Huebener, M. Mihailescu, U. Cubasch, and P. Stanciu, 2014: A Hidden Markov Model Applied to the Daily Spring Precipitation over the Danube Basin. Advances in Meteorology, Volume 2014 (2014), Article ID 237247, 11 pp, dx.doi.org/10.1155/2014/237247 * Regional derivation of daily spring precipitation * Polanski, S., B. Fallah, D. J. Befort, S. Prasad and U. Cubasch, 2014: Regional moisture change over India during the past Millenium: A comparison of multi-proxy reconstructions and climate model simulations. Global and Planetary Change, 122, 176-185, , dx.doi.org.10.1016/J.gloplacha.2014.08.016 * regional moisture variability during the past millennium over India * Sommerfeld, A., K. Prömmel and U. Cubasch, 2014: The East African Rift System and the impact of orographic changes on regional climate and the resulting aridification. Int. J. Earth Sci, , DOI 10.1007.200531-014-1102-x * regional orographic effects on the hydrological cycle * Fallah, B. and U. Cubasch, 2015: A comparison of model simulations of Asian mega-droughts during the past millennium with proxy reconstructions, Clim. Past, 11, 253-263, doi:10.5194/cp-11-253-2015 * Analysis of mega droughts in models and observational (proxy) data during the last millennium * Fallah, B, S. Sodoudi and U. Cubasch, 2015: Westerly jet stream and past millenium climate change in Arid Central Asia simulated by COSMO-CLM model. , DOI 10.1007/s00704-015-1479-x * natural regional climate variability and extremes * Befort, D. J., G. C. Leckebusch and U. Cubasch, 2016: Intraseasonal variability of the Indian summer monsoon: wet and dry events in COSMO-CLM. , DOI 10.1007/s00382-016-2989-7 * intraseasonal variability of Indian summer monsoon in regional model simulation * Babian, S., H. W. Rust, J. Grieger, K. Prömmel and U. Cubasch, 2016: Representation of the Antarctic Oscillation and related precipitation patterns in the MPI Earth System Model, Met. Zeitschrift, , DOI 10.1127/metz/2016/0661 * Antarctic oscillation variability and modeled precipitation pattern * Wei Shang, Xuejuan Ren, Bo Huang, Ulrich Cubasch and Xiu-qun Yang, 2018: Subseasonal intensity variations of the South Asian high in relationship to diabatic heating: observation and CMIP5 models. Clim. Dyn, doi.org/10.1007/s00382-018-4266-4 * Linking regional sub seasonal variability with diabetic heat sources * Bo Huang, Ulrich Cubasch and Yan Li, 2018: East-Asian Summer Monsoon Representation in Re-Analysis Datasets. Atmosphere, 9, 235, , doi:10.3390/atmos9060235 * Evaluation of the description of the regional variability in different re-analysis Dara sets * Zanchettin, D., Khodri, M., Timmreck, C., Toohey, M., Schmidt, A., Gerber, E. P., Hegerl, G., Robock, A., Pausata, F. S. R., Ball, W. T., Bauer, S. E., Bekki, S., Dhomse, S. S., LeGrande, A. N., Mann, G. W., Marshall, L., Mills, M., Marchand, M., Niemeier, U., Poulain, V., Rozanov, E., Rubino, A., Stenke, A., Tsigaridis, K., and Tummon, F.: The Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP): experimental design and forcing input data for CMIP6, Geosci. Model Dev., 9, 2701-2719, doi:10.5194/gmd-9-2701-2016, 2016, 10.5194/gmd-9-2701-2016, 2016 * This paper presents the experimental design of the "Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP), which includes idealized experiments focused on the short-term atmospheric as well as long-term coupled response to volcanic forcing. The core idea of VolMIP is to constrain radiative forcing among the participating models to focus on the climatic response, hence reference forcing dataare provided in terms of optical aerosol properties for a series of reference eruptions. * Khodri M., Izumo T., Vialard J., Janicot S., Cassou C., Lengaigne M., Mignot J., Gastineau G., E. Guilyardi, Lebas N., Robock A. and M.J McPhaden, Tropical explosive volcanic eruptions can trigger El Niño by cooling tropical Africa, Nature Communications, 8, 778 (2017). , 10.1038/s41467-017-00755-6 * This paper presents new evidences for a possible interference of volcanic forcing from tropical stratospheric eruptions on ENSO cycle and discusses the underlying physical processes. Targeted climate model simulations emphasize that Pinatubo-like eruptions tend to shorten La Niñas, lengthen El Niños and induce anomalous warming when occurring during neutral states. It also presents a new mechanisms suggesting that volcanically induced cooling in tropical Africa weakens the West African monsoon, and the resulting atmospheric Kelvin wave can drive equatorial westerly wind anomalies over the western Pacific. This wind anomaly is further amplified by air-sea interactions in the Pacific, favouring an El Niño-like response. * Lora, J.M. (2018).Components and mechanisms of hydrologic cycle changes over North America at the Last Glacial Maximum. Journal of Climate 31, 7035-7051, https://doi.org/10.1175/JCLI-D-17-0544.1 * This paper provides a full moisture budget analysis of North America during the LGM, which gives context for and a comparison point for similar analyses of future hydroclimate changes. * Lora, J.M., J.L. Mitchell, and A.E. Tripati (2016). Abrupt reorganization of North Pacific and western North American climate during the last deglaciation, https://doi.org/10.1002/2016GL071244 * This paper describes an abrupt reorganization of the circulation during the last deglaciation that lead to hydroclimate changes in western North America observed in proxies. * Lora, J.M., J.L. Mitchell, C. Risi, and A.E. Tripati (2017). North Pacific atmospheric rivers and their influence on North America at the Last Glacial Maximum. Geophysical Research Letters 44, 1051-1059, https://doi.org/10.1002/2016GL071541 * This paper shows the strong impact that changes in climatological atmospheric river activity had on mid-latitude hydroclimate at the LGM, providing context for such future changes. * Sun, Y. et al., 2018:Quantifying East Asian summer monsoon dynamics in the ECP4.5 scenario with reference to the mid-Piacenzian warm period. Geophysical Research Letters , https://doi.org/10.1029/2018GL080061 * A comparison of summer monsoon dynamics over East Asia for the mid-Piacenzian and the ECP4.5 scenario reveals both large-scale similarities and regional differences. a) Large-scale similarity in moisture transport under thermal control b) Regional differences in vertical motion regulated by moist static energy c) Negligible effect of slight topographic difference on regional precipitation * Yan Qing, Owen, L. A., Wang, H., & Zhang, Z. (2018). Climate constraints on glaciation over High-Mountain Asia during the last glacial maximum. Geophysical Research Letters, 45, 9024-9033., n/a * This paper addresses the questions on why there was not a large-scale ice sheet during LGM * Yan Qing, Wei Ting, and Zhang Zhongshi, 2017: Variations in large-scale tropical cyclone genesis factors over the western North Pacific in the PMIP3 last millennium simulations, Climate Dynamics, 48(3-4): 957-970., n/a * This paper examines the variation of tropical cyclone genesis during the last millennium * Lowry, D.P. and Morrill, C. 2018. Is the Last Glacial Maximum a reverse analog for future hydroclimate changes in the Americas? Climate Dynamics., 10.1007/s00382-018-4385-y * Future hydroclimate change is expected to generally follow a wet-get-wetter, dry-get-drier (WWDD) pattern, yet key uncertainties remain regionally and over land. We analyze 6 PMIP3 LGM simulations and show that, in some regions of North and South America, LGM hydroclimate changes could provide some insight into future changes in precipitation-evaporation. * Morrill, C., Lowry, D.P., Hoell, A. 2018. Thermodynamic and dynamic causes of pluvial conditions during the Last Glacial Maximum in Western North America. Geophysical Research Letters 45, 335-345., 10.1002/2017GL075807 * We analyze 9 PMIP3 simulations to argue that wet conditions in western North America at LGM were caused by a combination of dynamic and thermodynamic factors. These same factors, working in the opposite direction, are projected to cause regional drying in western North America under increased greenhouse gas concentrations, indicating continuity from past to future in the mechanisms altering hydroclimate. * Zheng, W. P. and Braconnot, P. (2013). Characterization of Model Spread in PMIP2 Mid-Holocene Simulations of the African Monsoon. Journal of Climate. 26: 1192-1210., https://doi.org/10.1175/JCLI-D-12-00071.1 * Using a classification of the monsoonal convective regimes fora subset of sevenPMIP mid Holocene simulations, this paper show that two categories of model can be defined based on their differences insimulating deep and moderate convective regimes in the PI simulations. Changes in precipitation at 6 ka are dominated by changes in the large-scale dynamics for most of the PMIP2 models and are characterized bya shift in the monsoonal circulation toward deeper convective regimes. The results indicate that systematic model biases in simulating the radiation and heat fluxes could explain the damping of the meridional temperature gradient over West Africa and thereby the underestimation of precipitation in the Sahel-Sahara region. * Marzin, C., Kallel, N., Kageyama, M., Duplessy, J. C. and Braconnot, P. (2013). Glacial fluctuations of the Indian monsoon and their relationship with North Atlantic climate: new data and modelling experiments. Climate of the Past. 9: 2135-2151, https://doi.org/10.5194/cp-9-2135-2013 * This study analyse the processes that can explain the relationship between the Indian monsoon and the North Atlantic climate under glacial conditions, by increasing the freshwater flux in the North Atlantic and reducing the intensity of the Atlantic meridional overturning circulation. It shows that reduced indian monsoon is associated to changes in the continental runoff and local hydrological cycle that are responsible for the changes in salinity of the Bay of Bengal in the model. Sensitivity experiments also highlight that the changes over the tropical Atlantic are essential in triggering perturbations of the subtropical jet over Eurasia that in turn affect the intensity of the Indian monsoon. * Marzin, C., Braconnot, P. and Kageyama, M. (2013). Relative impacts of insolation changes, meltwater fluxes and ice sheets on African and Asian monsoons during the Holocene. Climate Dynamics. 41: 2267-2286., https://doi.org/10.1007/s00382-013-1948-9 * This paper analyse the teleconnection between the remnant northern hemisphere ice-sheet in the early Holocene and fresh water fluxes induced by ice sheet melting on the African and Indian monsoons. It shows that despite similarities in the response to these two factors in the Atlantic the teleconnections are different, mainly because of differences in the way the thermohaline circulation is affected. * Luan, Y. H., et al. (2015). "Tropical Pacific mean state and ENSO changes: sensitivity to freshwater flux and remnant ice sheets at 9.5 ka BP." Climate Dynamics 44(3-4): 661-678., https://doi.org/10.1007/s00382-015-2467-7 * Using as a reference a simulation of the early Holocene, the present study explores the relative contribution of ice-sheet and fresh water fluxes on themean climate state and ENSO variability in the tropical Pacific.The freshwater flux impact on ocean circulation and atmospheric feedbacks enhances ENSO amplitude. A feedback analysis suggests that it is due to the wind-thermocline feedback. The remnant ice sheett does not induce significant change in ENSO. Itexhibits a slight SST variability increase at the east coast and a reduction in the middle of the basin driven by the net. The freshwater flux forcing strengthens the amplitude of EP El Niño events. This mansucripts halp thus to unerstand the diversity of EL Niño event and the response of El Niño to external forcings. * Saint-Lu, M., et al. (2015). "Changes in the ENSO/SPCZ relationship from past to future climates." Earth and Planetary Science Letters 412: 18-24., http://doi.org/10.1016/j.epsl.2014.12.033 * This study considers a set of paleoclimate and future climate simulations. It shows that changes in the background tropical state largely control the mean SPCZ location. In contrast, changes in the background tropical state do not directly control the interannual variability of the SPCZ location. The relationship between ENSO and the SPCZ location varies from one climate to another. We thus demonstrate that the teleconnection mechanisms inferred from the modern climate cannot be directly extrapolated to other climates. This study therefore calls for a cautious interpretation of climate reconstructions from environmental indicators in the Southwest Pacific with regard to ENSO variations. * Consequences of rapid ice-sheet melting on the Sahelian population vulnerability, D. Defrance, G. Ramstein, S. Charbit, M. Vrac, A.M. Famien, B. Sultan, D. Swingedouw, C. Dumas, F. Gemenne, J. Alvarez-Solas, J.-P. Vanderlinden, PNAS, 114 (25), 6533-6538, 2017, https://doi.org/10.1073/pnas.1619358114 * This paper describes the impact of massive Greenland ice-sheet melting on the West Sahelian monsoon system (with consequences on agriculture and population) * What drives LGM precipitation over the western Mediterranean? A stydy focused on the Iberian Peninsula and northern Morocco., P Beghin, S. Charbit, M. Kageyama, N. Combourieu-Nebout, C. Hatté, C. Dumas, J.-Y. Peterschmitt, Climate Dynamics, 46 (7-8), 2611-2631, 2016 , doi: 10.1007/s00382-015-2720-0, 2016 * This paper describes how changes in the North Atlantic jet stream (due to the presence of the North American ice sheet) during the LGM influences the precipitation in the Iberian Peninsula and Northern Morocco. The paper is based on a model-data comparison. * How might the North American ice sheet influence the northwestern European climate, P. Beghin, S. Charbit, C. Dumas, M. Kageyama, C. Ritz., Climate of the Past, 11, 1467-1490, 2015, https://doi.org/10.5194/cp-10-345-2014, 2014 * Describes how the growth of the North American ice sheet during the last glacial cycle influences the Eurasian ice sheet through atmospheric teleconnections * PAGES Hydro2k Consortium (J. E. Smerdon, J. Luterbacher, S. J. Phipps, K. J. Anchukaitis, T. Ault, S. Coats, K. M. Cobb, B. I. Cook, C. Colose, T. Felis, A. Gallant, J. H. Jungclaus, B. Konecky, A. LeGrande, S. Lewis, A. S. Lopatka, W. Man, J. S. Mankin, J. T. Maxwell, B. L. Otto-Bliesner, J. W. Partin, D. Singh, N. J. Steiger, S. Stevenson, J. E. Tierney, D. Zanchettin, H. Zhang, A. R. Atwood, L. Andreu-Hayles, S. H. Baek, B. Buckley, E. R. Cook, R. D'Arrigo, S. G. Dee, M. L. Griffiths, C. Kulkarni, Y. Kushnir, F. Lehner, C. Leland, H. W. Linderholm, A. Okazaki, J. Palmer, E. Piovano, C. C. Raible, M. P. Rao, J. Scheff, G. A. Schmidt, R. Seager, M. Widmann, A. P. Williams and E. Xoplaki): Comparing proxy and model estimates of hydroclimate variability and change over the Common Era, Climate of the Past, 13, 1851-1900, doi:10.5194/cp-13-1851-2017, 2017., 10.5194/cp-13-1851-2017 * We review the principal proxy data available for hydroclimatic reconstructionsover the Common Era (CE) and highlight the contemporary understanding of how these proxies are interpreted as hydroclimate indicators. We also review the available last-millennium simulations from fully coupled climate models and discuss several outstanding challenges associated with simulating hydroclimate variability and change over the CE. * Atsawawaranunt, K., Comas-Bru, L., Amirnezhad Mozhdehi, S., Deininger, M., Harrison, S.P., Baker, A., Boyd, M., Kaushal, N., Masood Ahmed, S., Arienzo, M., Brahim, Y.A., Bajo, P., Braun, K., Burstyn, Y., Chawchai, S., Duan, W., Hatvani, I.G., Hu, J., Kern, Z., Labuhn, I., Lachniet, M., Lechleiter, F.A., Lorrey, A., Pérez-Mejías, C., Pickering, R., Scroxton, N. and SISAL Working Group Members, 2018. The SISAL database: a global resource to document water and carbon isotope records from speleothems. Earth System Science Data 10:1687-1713. , https://doi.org/10.5194/essd-10-1687-2018 * Documents a new data set of oxygen isotope data from speleothems that will can be used for benchmarking isotope-enabled palaeoclimate simulations * Bartlein, P.J., S.P. Harrison and K. Izumi, 2017, Underlying causes of Eurasian mid-continental aridity in simulations of mid-Holocene climate, Geophysical Research Letters. 44:1-9, http://dx.doi.org/10.1002/2017GL074476 * Discusses a long-standing mismatch between climate-model simulations and paleo observations and relates these to present-day biases in atmospheric circulation and moisture flux * Prentice, I.C., Cleator, S.F., Huang, Y.F., Harrison, S.P., Roulstone, I., 2017. Reconstructing ice -age climates: quantifying low-CO2 effects on plants. Global and Planetary Change 149: 166-176., http://dx.doi.org/10.1016/j.gloplacha.2016.12.012 * Provides a way of taking account of the ecophysicological impacts of low CO2 during glacial periods in making climate reconstructions of moisture variables from fossil pollen. The water-use efficiency of plants in reduced under low CO2 and this results in vegetation appearing to reflect more arid conditions that in fact prevailed. The paper provides a correction which can be applied to existing pollen-based reconstructions of moisture to take account of this. * Perez-Sanz, A., Li, G., Gonzalez, P., Harrison, S.P., 2014. Evaluation of seasonal climates of northern Africa and the Mediterranean in the CMIP5 simulations. Climate of the Past 10: 551-568. doi:10.5194/cp-10-551-2014, doi:10.5194/cp-10-551-2014 * Provides an evaluation of the ability of the CMIP5 simulations to simukate enhanced monsoons during the mid-Holocene. * Li, G., S.P. Harrison, P.J. Bartlein, K. Izumi & I.C. Prentice, 2013, Precipitation scaling with temperature in warm and cold climates: an analysis of CMIP5 simulations. Geophysical Research Letters:, https://doi.org/10.1002/grl.50730 * Examines the systematic scaling of precipitation changes in warm and cold climates * Morrill, C., Meador, E., Livneh, B., Liefert, D.T., Shuman, B.N. 2019. Quantitative model-data comparison of mid-Holocene lake-level change in the central Rocky Mountains. Climate Dynamics. , 10.1007/s00382-019-04633-3 * We used several hydrologic forward models in a form of downscaling to quantitatively compare PMIP3 simulations with lake level records. We found that the severity of mid-Holocene drought in western/central North America about 6,000 years ago is consistent with local winter precipitation reductions of up to 50%, and that PMIP3 models fail to reproduce the severity of this drought. * Oster, J. L., Ibarra, D. E., Winnick, M. J., & Maher, K. (2015). Steering of westerly storms over western North America at the Last Glacial Maximum. Nature Geoscience, 8(3), 201., 10.1038/ngeo2365 * Evaluation of model (PMIP3/PMIP2) performance using paleoclimate data, constraints on precipitation change caused be climate forcing and P-E changes observed using paleoclimate records. * Ibarra, D. E., Oster, J. L., Winnick, M. J., Caves Rugenstein, J. K., Byrne, M. P., & Chamberlain, C. P. (2018). Warm and cold wet states in the western United States during the Pliocene-Pleistocene. Geology, 46(4), 355-358., 10.1130/G39962.1 * Water cycle and regional moisture energy balance budget change constrained by geologic/paleoclimate data and PMIP models in semi-arid region. * R D'Agostino, J Bader, S Bordoni, D Ferreira, J Jungclaus (2019): Northern Hemisphere Monsoon Response to Mid-Holocene Orbital Forcing and Greenhouse Gas-Induced Global Warming, Geophysical Research Letters 46 (3), 1591-1601, https://doi.org/10.1029/2018GL081589 * Mechanisms driving monsoon response to midHolocene orbital forcing and rcp8.5 greenhouse-induced global warming scenario are different. A decomposition of the moisture budget in thermodynamic and dynamic contributions suggests that under future global warming, the weaker response of the African, Indian, and North American monsoons results from a compensation between both components. The dynamic component, primarily constrained by changes in net energy input over land, determines instead most of the mid-Holocene land monsoonal rainfall response. This process-oriented study takes an important step toward improving our understanding of monsoon dynamics, quantifying the important role of atmospheric circulation changes in monsoonal precipitation changes by comparing and contrasting past and future climates. Our results highlight that mean surface warming and interhemispheric contrast in surface warming are poor indicators of the monsoonal precipitation response. Rather, the monsoon response is constrained by the integrated energy balance, which accounts for changes at the surface as well as at the top of the atmosphere. This explains why the mid-Holocene does not represent an analogue for future warming. * A.Kislov. On the interpretation of century-millennium-scale variations of the Black Sea level during the first quarter of the Holocene. Quaternary International. Volume 465, Part A, 2018, Pages 99-104., https://doi.org/10.1016/j.quaint.2016.09.008 * model-data, and data syntheses * Kislov A. The interpretation of secular Caspian Sea level records during the Holocene Quaternary International, 2016, vol. 409, 39-43 , https://doi.org/10.1016/j.quaint.2015.07.026 * data syntheses : * Yanko-Hombach, V., Kislov, A., Late Pleistocene and Holocene sea-level dynamics in the Caspian and Black Seas: Data synthesis and Paradoxical interpretations, Quaternary International (2017) , https://doi.org/10.1016/j.quaint.2017.11.030 * model-data, and data syntheses * Kislov A. 2018 Secular Variability of the Caspian Sea Level. Russian Meteorology and Hydrology, vol. 43, No 10, 679-685 , 10.3103/S1068373918100072 * data syntheses ===== Chapter 9: Ocean, Cryosphere, and Sea Level Change ===== Number of selected references: **42** * Muglia, J., and Schmittner, A. (2015)Glacial Atlantic overturning increased by wind stress in climate modelsGeophysical Research Letters, 42., https://doi.org/10.1002/2015GL064583 * It demonstrates challenges of climate models to simulate past deep ocean circulation. * Koenig, S. J., Dolan, A. M., de Boer, B., Stone, E. J., Hill, D. J., DeConto, R. M., Abe-Ouchi, A., Lunt, D. J., Pollard, D., Quiquet, A., Saito, F., Savage, J., and van de Wal, R., 2015. Ice sheet model dependency of the simulated Greenland Ice Sheet in the mid-Pliocene, Clim. Past, 11, 369--381., https://doi.org/10.5194/cp-11-369-2015 * This paper shows the first results of the Pliocene Ice Sheet modeling intercomparison Project for the Greenland ice sheets, how simulations of the GrIS depend on climate forcing and uncertainties in Pliocene ice-sheet predictions. * de Boer, B., Dolan, A. M., Bernales, J., Gasson, E., Goelzer, H., Golledge, N. R., Sutter, J., Huybrechts, P., Lohmann, G., Rogozhina, I., Abe-Ouchi, A., Saito, F., and van de Wal, R. S. W., 2015. Simulating the Antarctic ice sheet in the late-Pliocene warm period: PLISMIP-ANT, an ice-sheet model intercomparison project, The Cryosphere, 9, 881--903., https://doi.org/10.5194/tc-9-881-2015 * The results of the Pliocene Ice Sheet Modeling Intercomparison project for Antarctica. The paper demonstrates the uncertainties in ice-sheet model predictions for the Pliocene, depending on which ice-sheet model is used. Includes prediction of sea level. * Dolan, Aisling M., de Boer, Bas, Bernales, Jorge, Hill, Daniel J., and Haywood, Alan M., 2018. High climate model dependency of Pliocene Antarctic ice-sheet predictions, Nature Communications, 9:2799., https://doi.org/10.1038/s41467-018-05179-4 * Final PLISMIP paper. Using climatological forcing from 7 PlioMIP, AO-GCM simulations, for 3 ice-sheet models, the paper demonstrates the high dependency of Antarctic ice-sheet volume predictions on the climatemodel-based forcing used. * de Boer, Bas, Haywood, Alan M., Dolan, Aisling M., Hunter, Stephen J., and Prescott, Caroline L., 2017. The Transient Response of Ice Volume to Orbital Forcing During the Warm Late Pliocene, Geophysical Research Letters, 44, 10,486--10,494., https://doi.org/10.1002/2017GL073535 * The paper presents transient ice sheet predictions forced by multiple climate snapshots derived from HadCM3 set up with late Pliocene boundary conditions, forced with different orbital forcing scenarios. The results indicate that insolation forcing between the hemispheres was out of phase during MIS K1 and led to an asynchronous response of ice volume globally. * Langebroek, P. M. and Nisancioglu, K. H., 2014: Simulating last interglacial climate with NorESM: role of insolation and greenhouse gases in the timing of peak warmth, Clim. Past, 10, 1305-1318. , https://doi.org/10.5194/cp-10-1305-2014 * It shows the difference in impact of insolation versus greenhouse gas forcing on the (timing of peak) warmth during the last interglacial. Global simulations using the Norwegian Earth System Model, with a focus on explaining proxy records in the North Atlantic. * Otto-Bliesner, B.L. et al., 2017: The PMIP4 contribution to CMIP6 - Part 2: Two interglacials, Scientific objectives and experimental design of the PMIP4-CMIP6 Holocene and Last Interglacial simulations. Geoscientific Model Development, 10, 3979-4003, https://doi.org/10.5194/gmd-10-3979-2017 * This paper describes the protocols for the mid-Holocene (6 ka) and Last Interglacial (127 ka) Tier 1 simulations, as well as numerous Tier 2 simulations to assess the sensitivities to prescribed vegetation, ice sheets, freshwater fluxes, and alternative states of orbital forcing. For the first time, the LIG is included for CMIP6 and PMIP4, allowing a multi-model assessment of this important period for testing our knowledge of climate-ice sheet interactions in warm climates. * Capron, E., A. Govin, R. Feng, B.L. Otto-Bliesner, and E.W. Wolff, 2017: Critical evaluation of climate syntheses to benchmark CMIP6/PMIP4 127 ka Last Interglacial simulations in the high-latitude regions, n/a * This study provides a data-based regional temperature estimates across the Last Interglacial above the polar ice sheets and at the surface of the North Atlantic and Southern oceans. It highlights a strong polar amplification and land-sea contrast processes at play during this warm past time interval. * Fasullo, J.T., R. Tomas, S. Stevenson, B. Otto-Bliesner, E. Brady, E. Wahl, 2017: The amplifying influence of increased ocean stratification on a future year without a summer, Nature Communications, 8, 1236. doi:10.1038/s41467-017-01302-z, https://doi.org/10.1038/s41467-017-01302-z * CESM simulations of both the 1815 Tambora eruption and a hypothetical analogous future eruption are compared, the latter occurring in 2085 assuming a business-as-usual climate scenario. The 1815 eruption drove strong responses in both the ocean and cryosphere that were fundamental to driving the Year-Without-A-Summer. Through modulation of ocean stratification and near-surface winds, global warming contributes to an amplified surface climate response in CESM. * Zhu, J., Z.Y. Liu, E.C. Brady, B.L. Otto-Bliesner, S.A. Marcott, J. Zhang, A. Wang, D. Noone, R. Tomas, J. Nusbaumer, T. Wong, A. Jahn, and C. Tabor, 2017: Reduced ENSO variability at the LGM revealed by an isotope-enabled Earth system model. Geophysical Research Letters, 44, 6984-6992., n/a * Paleoclimate reconstructions and model simulations of ENSO strength at the Last Glacial Maximum (LGM; 21 ka B.P.) have led to contradicting conclusions. Using simulations from the water isotope-enabled Community Earth System Model (iCESM), this paper shows that the LGM ENSO is most likely weaker than the preindustrial and that ENSO reconstructions using the individual foraminifera analysis may reflect changes in the annual cycle instead of ENSO variability * Zhu, J., Z.Y. Liu, E. Brady, B. Otto-Bliesner, J.X. Zhang, J. Nusbaumer, T.E. Wong, A. Jahn, and D. Noone, 2017: Investigating the direct meltwater effect in terrestrial oxygen-isotope paleoclimate records using an isotope-enabled Earth system model. Geophysical Research Letters, 44, 12501-12510., https://doi.org/10.1002/2017GL076253 * Variations in terrestrial oxygen-isotope reconstructions from ice cores and speleothems have been primarily attributed to climatic changes of surface air temperature, precipitation amount, or atmospheric circulation. New modeling results with the water isotope-enabled CESM suggest important nuances for past climate interpretations of delta18O. * Zanchettin, D., O. Bothe, H. F. Graf, S. J. Lorenz, J. Luterbacher, C. Timmreck, and J. H. Jungclaus (2013) Background conditions influence the decadal climate response to strong volcanic eruptions. J. Geophys. Res. Atm., 118(10): 4090-4106, doi:10.1002/jgrd.50229, 10.1002/jgrd.50229 * This study illustrates how the decadal climate response to strong volcanic eruptions depends on the background climate state at the time of the eruption and on the presence and magnitude of additional external forcings acting at the same time. It demonstrates that background climate conditions are not merely a source of additive noise for post-eruption decadal climate variability but actively influence the mechanisms involved in the post-eruption decadal evolution. * Yan Qing, Owen, L. A., Wang, H., & Zhang, Z. (2018). Climate constraints on glaciation over High-Mountain Asia during the last glacial maximum. Geophysical Research Letters, 45, 9024-9033., n/a * This paper addresses the questions on why there was not a large-scale ice sheet during LGM * Yan Qing, Wei Ting, and Zhang Zhongshi, 2017: Variations in large-scale tropical cyclone genesis factors over the western North Pacific in the PMIP3 last millennium simulations, Climate Dynamics, 48(3-4): 957-970., n/a * This paper examines the variation of tropical cyclone genesis during the last millennium * Harrison, S. P., Bartlein, P. J., Izumi, K., Li, G., Annan, J., Hargreaves, J., et al. (2015). Evaluation of CMIP5 palaeo-simulations to improve climate projections. Nature Climate Change, 5(8), 735-743. , http://doi.org/10.1038/nclimate2649 * Past climate changes provide a unique opportunity for out-of-sample evaluation of model performance. Palaeo-evaluation has shown that the large-scale changes seen in twenty-first-century projections, including enhanced land-sea temperature contrast, latitudinal amplification, changes in temperature seasonality and scaling of precipitation with temperature, are likely to be realistic. * Grunseich, G. and Wang, B., 2016. Arctic sea ice patterns driven by the Asian summer monsoon. Journal of Climate, 29(24), pp.9097-9112., 10.1175/JCLI-D-16-0207.1 * This work finds sources of variability in the Arctic sea ice. * Grunseich, G. and Wang, B., 2016. Predictability of Arctic annual minimum sea ice patterns. Journal of Climate, 29(19), pp.7065-7088., 10.1175/JCLI-D-16-0102.1 * This work finds sources of variability of the Arctic sea ice. * Schmidt, G. A., Annan, J. D., Bartlein, P. J., Cook, B. I., Guilyardi, E., Hargreaves, J. C., et al. (2014). Using palaeo-climate comparisons to constrain future projections in CMIP5. Climate of the Past, 10(1), 221-250. , http://doi.org/10.5194/cp-10-221-2014 * Using palaeo-climate comparisons to constrain future projections! * Zheng, W. P. and Braconnot, P. (2013). Characterization of Model Spread in PMIP2 Mid-Holocene Simulations of the African Monsoon. Journal of Climate. 26: 1192-1210., https://doi.org/10.1175/JCLI-D-12-00071.1 * Using a classification of the monsoonal convective regimes fora subset of sevenPMIP mid Holocene simulations, this paper show that two categories of model can be defined based on their differences insimulating deep and moderate convective regimes in the PI simulations. Changes in precipitation at 6 ka are dominated by changes in the large-scale dynamics for most of the PMIP2 models and are characterized bya shift in the monsoonal circulation toward deeper convective regimes. The results indicate that systematic model biases in simulating the radiation and heat fluxes could explain the damping of the meridional temperature gradient over West Africa and thereby the underestimation of precipitation in the Sahel-Sahara region. * Marzin, C., Kallel, N., Kageyama, M., Duplessy, J. C. and Braconnot, P. (2013). Glacial fluctuations of the Indian monsoon and their relationship with North Atlantic climate: new data and modelling experiments. Climate of the Past. 9: 2135-2151, https://doi.org/10.5194/cp-9-2135-2013 * This study analyse the processes that can explain the relationship between the Indian monsoon and the North Atlantic climate under glacial conditions, by increasing the freshwater flux in the North Atlantic and reducing the intensity of the Atlantic meridional overturning circulation. It shows that reduced indian monsoon is associated to changes in the continental runoff and local hydrological cycle that are responsible for the changes in salinity of the Bay of Bengal in the model. Sensitivity experiments also highlight that the changes over the tropical Atlantic are essential in triggering perturbations of the subtropical jet over Eurasia that in turn affect the intensity of the Indian monsoon. * Howell, F. W., Haywood, A. M., Otto-Bliesner, B. L., Bragg, F., Chan, W.-L., Chandler, M. A., Contoux, C., Kamae, Y., Abe-Ouchi, A., Rosenbloom, N. A., Stepanek, C. and Zhang, Z.: Arctic sea ice simulation in the PlioMIP ensemble, Clim. Past, 12, 749-767, doi:10.5194/cp-12-749-2016, 2016., http://doi.org/10.5194/cp-12-749-2016 * This paper describes the response of Artic sea-ice to the Pliocene warm climate (PlioMIP1) into 8 general circulation models * Lunt, D. J., A. Abe-Ouchi, P. Bakker, A. Berger, P. Braconnot, S. Charbit, N. Fischer, N. Herold, J. H. Jungclaus, V. C. Khon, U. Krebs-Kanzow, P. M. Langebroek, G. Lohmann, K. H. Nisancioglu, B. Otto-Bliesner, W. Park, M. Pfeiffer, S. J. Phipps, M. Prange, R. Rachmayani, H. Renssen, N. Rosenbloom, B. Schneider, E. J. Stone, K. Takahashi, W. Wei, Q. Yin and Z. S. Zhang: A multi-model assessment of last interglacial temperatures, Climate of the Past, 9, 699-717, doi:10.5194/cp-9-699-2013, 2013., 10.5194/cp-9-699-2013 * Examines the PMIP3 simulations of the Last Interglacial and finds that the models do not agree well with reconstructions. In particular, the models fail to replicate the reconstructed warming at high latitudes. * Bakker, P., V. Masson-Delmotte, B. Martrat, S. Charbit, H. Renssen, M. Gröger, U. Krebs-Kanzow, G. Lohman, D. J. Lunt, M. Pfeiffer, S. J. Phipps, M. Prange, S. P. Ritz, M. Schulz, B. Stenni, E. J. Stone and V. Varma: Temperature trends during the Present and Last Interglacial periods - a multi-model-data comparison, Quaternary Science Reviews, 99, 224-243, doi:10.1016/j.quascirev.2014.06.031, 2014., 10.1016/j.quascirev.2014.06.031 * The reconstructed Present Interglacial (PIG) and Last Interglacial (LIG) Northern Hemisphere mid-to-high latitude cooling compares well with multi-model, mean temperature trends for the warmest months and that these cooling trends reflect a linear response to the warmest-month insolation decrease over the interglacial intervals. The most notable exception is the strong LIG cooling trend reconstructed from Greenland ice cores that is not simulated by any of the models. A striking model-data mismatch is found for both the PIG and the LIG over large parts of the mid-to-high latitudes of the Southern Hemisphere where the data depicts negative temperature trends that are not in agreement with near zero trends in the simulations. * McGregor, H. V., M. N. Evans, H. Goosse, G. Leduc, B. Martrat, J. A. Addison, P. G. Mortyn, D. W. Oppo, M.-S. Seidenkrantz, M.-A. Sicre, S. J. Phipps, K. Selveraj, K. Thirumalai, H. L. Filipsson and V. Ersek: Robust global ocean cooling trend for the pre-industrial Common Era, Nature Geoscience, 8, 671-677, doi:10.1038/NGEO2510, 2015., 10.1038/NGEO2510 * Here we present a global synthesis of sea surface temperatures for the Common Era (CE) derived from 57 individual marine reconstructions that meet strict quality control criteria. We observe a cooling trend from 1 to 1800 CE that is robust against explicit tests for potential biases in the reconstructions. Climate simulations using single and cumulative forcings suggest that the ocean surface cooling trend from 801 to 1800 CE is not primarily a response to orbital forcing but arises from a high frequency of explosive volcanism. Our results show that repeated clusters of volcanic eruptions can induce a net negative radiative forcing that results in a centennial and global scale cooling trend via a decline in mixed-layer oceanic heat content. * Ackerley, D., J. Reeves, C. Barr, H. Bostock, K. Fitzsimmons, M.-S. Fletcher, C. Gouramanis, H. McGregor, S. Mooney, S. J. Phipps, J. Tibby and J. Tyler: Evaluation of PMIP2 and PMIP3 simulations of mid-Holocene climate in the Indo-Pacific, Australasian and Southern Ocean regions, Climate of the Past, 13, 1661-1684, doi:10.5194/cp-13-1661-2017, 2017., 10.5194/cp-13-1661-2017 * Shows that the PMIP2/PMIP3 models and proxies agree on the differences in climate state for 6 ka relative to 0 ka, when they are insolation driven. The largest uncertainty between the models and the proxies occurs over the Indo-Pacific Warm Pool (IPWP). * Kageyama, M., P. Braconnot, S. P. Harrison, A. M. Haywood, J. H. Jungclaus, B. L. Otto-Bliesner, J.-Y. Peterschmitt, A. Abe-Ouchi, S. Albani, P. J. Bartlein, C. Brierley, M. Crucifix, A. Dolan, L. Fernandez-Donado, H. Fischer, P. O. Hopcroft, R. F. Ivanovic, F. Lambert, D. J. Lunt, N. M. Mahowald, W. R. Peltier, S. J. Phipps, D. M. Roche, G. A. Schmidt, L. Tarasov, P. J. Valdes, Q. Zhang and T. Zhou: The PMIP4 contribution to CMIP6 - Part 1: Overview and over-arching analysis plan, Geoscientific Model Development, 11, 1033-1057, doi:10.5194/gmd-11-1033-2018, 2018., 10.5194/gmd-11-1033-2018 * Simulations of five different periods have been designed to address the objectives of the sixth phase of the Coupled Model Intercomparison Project (CMIP6): the millennium prior to the industrial epoch (CMIP6 name: past1000); the mid-Holocene, 6000 years ago (midHolocene); the Last Glacial Maximum, 21 000 years ago (lgm); the Last Interglacial, 127 000 years ago (lig127k); and the mid-Pliocene Warm Period, 3.2 million years ago (midPliocene-eoi400). This paper describes the motivation for the choice of these periods and the design of the numerical experiments and database requests, with a focus on their novel features compared to the experiments performed in previous phases of PMIP and CMIP. It also outlines the analysis plan that takes advantage of the comparisons of the results across periods and across CMIP6 in collaboration with other MIPs. * Meyer, H., Opel, T., Laepple, T., Dereviagin, A. Y., Hoffmann, K. and Werner, M.: Long-term winter warming trend in the Siberian Arctic during the mid- to late Holocene, Nature Geoscience, 8(2), 122-125, doi:10.1038/ngeo2349, 2015., 10.1038/ngeo2349 * The paper presents a record of the oxygen isotope composition of permafrost ice wedges from the Siberian Arctic. In agreement with most PIMP3 models, the record shows a winter warming trend during the mid- to late Holocene, opposing the cooling seen in other proxy records. * Stenni, B., Curran, M. A. J., Abram, N. J., Orsi, A., Goursaud, S., Masson-Delmotte, V., Neukom, R., Goosse, H., Divine, D., Ommen, T. V., Steig, E. J., Dixon, D. A., Thomas, E. R., Bertler, N. A. N., Isaksson, E., Ekaykin, A., Werner, M. and Frezzotti, M.: Antarctic climate variability on regional and continental scales over the last 2000 years, Clim. Past, 13(11), 1609-1634, doi:10.5194/cp-13-1609-2017, 2017., 10.5194/cp-13-1609-2017 * The paper presents a most recent compilation of water stable isotope records from Antarctica, analysing climate variability on regional and continental scales over the last 2000 years. It shows that only for the Antarctic Peninsula the most recent century-scale warming trend is unusual in the context of natural variability over the last 2000 years. * Maier, E., Zhang, X., Werner, M., Gersonde, R., Mulitza, S., Méheust, M., Ren, J., Chapligin, B., Meyer, H., Stein, R., Tiedemann, R. and Lohmann, G.: North Pacific freshwater events linked to changes in glacial ocean circulation, Nature, 559(7713), 241-245, doi:10.1038/s41586-018-0276-y, 2018., 10.1038/s41586-018-0276-y * This study reveals that there was a strong connection between changes in North Atlantic circulation during Heinrich Stadials and injections of freshwater from the North American Cordilleran Ice Sheet to the north-eastern North Pacific. The results show that nonlinear ocean- atmosphere background interactions played a complex role in the dynamics linking the freshwater discharge responses of the North Atlantic and North Pacific during glacial periods. * Werner, M., Jouzel, J., Masson-Delmotte, V. and Lohmann, G.: Reconciling glacial Antarctic water stable isotopes with ice sheet topography and the isotopic paleothermometer, Nature Communications, 9(1), 3537, doi:10.1038/s41467-018-05430-y, 2018., 10.1038/s41467-018-05430-y * The study compares different glacial maximum ice sheet reconstructions of Antarctica by using an isotope-enabled high-resolution atmosphere GCM. A best model data match is achieved for the PMIP3 reconstruction. Furthermore, the performed modern and glacial climate simulations support the validity of the isotopic paleothermometer approach based on the use of present-day observations. * Goelzer, H., Huybrechts, P., Loutre, M. F., and Fichefet, T.: Impact of ice sheet meltwater fluxes on the climate evolution at the onset of the Last Interglacial, Clim. Past, 12, 1721-1737, doi:10.5194/cp-12-1721-2016, 2016., https://doi.org/10.5194/cp-12-1721-2016 * This paper shows modelling evidence that freshwater fluxes from the ice sheets are an important driver for climate changes at the onset of the Last Interglacial. * Goelzer, H., Huybrechts, P., Loutre, M. F., and Fichefet, T.: Last Interglacial climate and sea-level evolution from a coupled ice sheet-climate model, Clim. Past, 12, 2195-2213, doi:10.5194/cp-12-2195-2016, 2016., https://doi.org/10.5194/cp-12-2195-2016 * The paper describes one of the first attempts of a fully coupled transient climate-ice sheet simulation of the Last Interglacial period. The results suggest that the relative timing of sea-level contributions from the Greenland and Antarctic ice sheets are important for the interpretation of paleo sea-level records from that period. * Ziemen, F.A. et al., 2019: Heinrich events show two-stage climate response in transient glacial simulations. Clim. Past, 15, 153-168, 10.5194/cp-15-153-2019 * In previous Heinrich event studies, the climate changes were either seen as resulting from freshwater released from the melt of the discharged icebergs or by ice sheet elevation changes. With a coupled ice sheet-climate model, we show that both effects are relevant with the freshwater effects preceding the ice sheet elevation effects. * Goelzer, H., Huybrechts, P., Loutre, M. F., and Fichefet, T.: Last Interglacial climate and sea-level evolution from a coupled ice sheet-climate model, Clim. Past, 12, 2195-2213, doi:10.5194/cp-12-2195-2016, 2016., 10.5194/cp-12-2195-2016 * First fully coupled ice sheet-climate simulation of the LIG considering sea-level contributions from the Greenland and Antarctic ice sheets in a consistent framework. * Goelzer, H., Huybrechts, P., Loutre, M. F., and Fichefet, T.: Impact of ice sheet meltwater fluxes on the climate evolution at the onset of the Last Interglacial, Clim. Past, 12, 1721-1737, doi:10.5194/cp-12-1721-2016, 2016., 10.5194/cp-12-1721-2016 * Paper highlights the important role of freshwater fluxes for the climate, ice sheet and sea-level evolution at the onset of the last Interglacial. * Chandan and Peltier, 2017: Regional and global climate for the mid-Pliocene using the University of Toronto version of CCSM4 and PlioMIP2 boundary conditions. Climate of the Past, 13, 919-942, https://doi.org/10.5194/cp-13-919-2017 * This paper reports on the first time that an un-tuned coupled-climate model has reproduced with very high fidelity the features of the mid-Pliocene warm period. * Chandan and Peltier 2018: On the mechanisms of warming the mid-Pliocene and the inference of a hierarchy of climate sensitivities with relevance to the understanding of climate futures. Climate of the past, 14, 825-856, https://doi.org/10.5194/cp-14-825-2018 * This paper derives a hierarchy of climate sensitivities, applicable on various timescales, from modelling studies of the future-like warm period of the mid-Pliocene. * Yoshimori, M. and Suzuki, M.: The relevance of mid-Holocene Arctic warming to the future, Clim. Past, 15, 1375-1394, https://doi.org/10.5194/cp-15-1375-2019, 2019., 10.5194/cp-15-1375-2019 * The paper provides a physical basis of why the mid-Holocene Arctic warming information is useful for the future, i.e., paleo-constraint for the future. * A.Kislov. On the interpretation of century-millennium-scale variations of the Black Sea level during the first quarter of the Holocene. Quaternary International. Volume 465, Part A, 2018, Pages 99-104., https://doi.org/10.1016/j.quaint.2016.09.008 * model-data, and data syntheses * Kislov A. The interpretation of secular Caspian Sea level records during the Holocene Quaternary International, 2016, vol. 409, 39-43 , https://doi.org/10.1016/j.quaint.2015.07.026 * data syntheses : * Yanko-Hombach, V., Kislov, A., Late Pleistocene and Holocene sea-level dynamics in the Caspian and Black Seas: Data synthesis and Paradoxical interpretations, Quaternary International (2017) , https://doi.org/10.1016/j.quaint.2017.11.030 * model-data, and data syntheses * Kislov A. 2018 Secular Variability of the Caspian Sea Level. Russian Meteorology and Hydrology, vol. 43, No 10, 679-685 , 10.3103/S1068373918100072 * data syntheses ===== Chapter 10: Linking Global to Regional Climate Change ===== Number of selected references: **64** * Zhu, J., Z.Y. Liu, E.C. Brady, B.L. Otto-Bliesner, S.A. Marcott, J. Zhang, A. Wang, D. Noone, R. Tomas, J. Nusbaumer, T. Wong, A. Jahn, and C. Tabor, 2017: Reduced ENSO variability at the LGM revealed by an isotope-enabled Earth system model. Geophysical Research Letters, 44, 6984-6992., n/a * Paleoclimate reconstructions and model simulations of ENSO strength at the Last Glacial Maximum (LGM; 21 ka B.P.) have led to contradicting conclusions. Using simulations from the water isotope-enabled Community Earth System Model (iCESM), this paper shows that the LGM ENSO is most likely weaker than the preindustrial and that ENSO reconstructions using the individual foraminifera analysis may reflect changes in the annual cycle instead of ENSO variability * Zhu, J., Z.Y. Liu, E. Brady, B. Otto-Bliesner, J.X. Zhang, J. Nusbaumer, T.E. Wong, A. Jahn, and D. Noone, 2017: Investigating the direct meltwater effect in terrestrial oxygen-isotope paleoclimate records using an isotope-enabled Earth system model. Geophysical Research Letters, 44, 12501-12510., https://doi.org/10.1002/2017GL076253 * Variations in terrestrial oxygen-isotope reconstructions from ice cores and speleothems have been primarily attributed to climatic changes of surface air temperature, precipitation amount, or atmospheric circulation. New modeling results with the water isotope-enabled CESM suggest important nuances for past climate interpretations of delta18O. * Mares, C., I. Mares, H. Huebener, M. Mihailescu, U. Cubasch, and P. Stanciu, 2014: A Hidden Markov Model Applied to the Daily Spring Precipitation over the Danube Basin. Advances in Meteorology, Volume 2014 (2014), Article ID 237247, 11 pp, dx.doi.org/10.1155/2014/237247 * Regional derivation of daily spring precipitation * Polanski, S., B. Fallah, D. J. Befort, S. Prasad and U. Cubasch, 2014: Regional moisture change over India during the past Millenium: A comparison of multi-proxy reconstructions and climate model simulations. Global and Planetary Change, 122, 176-185, , dx.doi.org.10.1016/J.gloplacha.2014.08.016 * regional moisture variability during the past millennium over India * Sommerfeld, A., K. Prömmel and U. Cubasch, 2014: The East African Rift System and the impact of orographic changes on regional climate and the resulting aridification. Int. J. Earth Sci, , DOI 10.1007.200531-014-1102-x * regional orographic effects on the hydrological cycle * Fallah, B. and U. Cubasch, 2015: A comparison of model simulations of Asian mega-droughts during the past millennium with proxy reconstructions, Clim. Past, 11, 253-263, doi:10.5194/cp-11-253-2015 * Analysis of mega droughts in models and observational (proxy) data during the last millennium * Fallah, B, S. Sodoudi and U. Cubasch, 2015: Westerly jet stream and past millenium climate change in Arid Central Asia simulated by COSMO-CLM model. , DOI 10.1007/s00704-015-1479-x * natural regional climate variability and extremes * Bo Huang, S. Polanski and U. Cubasch, 2015: Assessment of precipitation climatology in an ensemble of CORDEX-East Asia regional climate simulations. Clim Res Vol. 64: 141-158, doi: 10.3354/cr01302 * precipitation climatology of models in CORDEX East Asia region * Fallah, B., U. Cubasch, K. Prömmel, S. Sodoudi, 2015: A numerical model study on the behaviour of Asian summer monsoon and AMOC due to orographic forcing of Tibetan Plateau. Clim. Dyn, DOI 10.1007/s00382-015-2914-5. * link between AMOC and Asian summer monsoon * Befort, D. J., G. C. Leckebusch and U. Cubasch, 2016: Intraseasonal variability of the Indian summer monsoon: wet and dry events in COSMO-CLM. , DOI 10.1007/s00382-016-2989-7 * intraseasonal variability of Indian summer monsoon in regional model simulation * Otto-Bliesner, B.L. et al., 2017: The PMIP4 contribution to CMIP6 - Part 2: Two interglacials, Scientific objectives and experimental design of the PMIP4-CMIP6 Holocene and Last Interglacial simulations. Geoscientific Model Development, 10, 3979-4003, doi:10.5194/cp-12-1645-2016 * regional temperature evolution over Europe during the Holocene * Babian, S., H. W. Rust, J. Grieger, K. Prömmel and U. Cubasch, 2016: Representation of the Antarctic Oscillation and related precipitation patterns in the MPI Earth System Model, Met. Zeitschrift, , DOI 10.1127/metz/2016/0661 * Antarctic oscillation variability and modeled precipitation pattern * Bal, S., S. Schimanke, T. Spangehl and U. Cubasch, 2017: Variable influence on the equatorial troposphere associated with SSW using ERA-interim. J. Earth. Sys. Sci., 126:19, DOI10.1007/sl2040-017-0802-6 * Natural variability of SSW and tropical troposphere * Xiaoli Chi, Rui Li, Ulrich Cubasch and Wenting Cao, 2017: The thermal comfort and its changes in the 31 provincial capital cities of mainland China in the past 30 years, Theoretical and Applied Climatology, 1-21, 10.1007/s00704-017-2099-4 * regional impact of climate change * Babian, S., J. Grieger and U. Cubasch, 2018: A new index for the wintertime southern hemisphere split jet. Atmos. Chem. Phys., 18, 6749-6760, doi.org/10.5194/acp-18-6749-2018 * improved description of southern hemisphere variability * Wei Shang, Xuejuan Ren, Bo Huang, Ulrich Cubasch and Xiu-qun Yang, 2018: Subseasonal intensity variations of the South Asian high in relationship to diabatic heating: observation and CMIP5 models. Clim. Dyn, doi.org/10.1007/s00382-018-4266-4 * Linking regional sub seasonal variability with diabetic heat sources * Bo Huang, Ulrich Cubasch and Yan Li, 2018: East-Asian Summer Monsoon Representation in Re-Analysis Datasets. Atmosphere, 9, 235, , doi:10.3390/atmos9060235 * Evaluation of the description of the regional variability in different re-analysis Dara sets * Zanchettin, D., Khodri, M., Timmreck, C., Toohey, M., Schmidt, A., Gerber, E. P., Hegerl, G., Robock, A., Pausata, F. S. R., Ball, W. T., Bauer, S. E., Bekki, S., Dhomse, S. S., LeGrande, A. N., Mann, G. W., Marshall, L., Mills, M., Marchand, M., Niemeier, U., Poulain, V., Rozanov, E., Rubino, A., Stenke, A., Tsigaridis, K., and Tummon, F.: The Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP): experimental design and forcing input data for CMIP6, Geosci. Model Dev., 9, 2701-2719, doi:10.5194/gmd-9-2701-2016, 2016, 10.5194/gmd-9-2701-2016, 2016 * This paper presents the experimental design of the "Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP), which includes idealized experiments focused on the short-term atmospheric as well as long-term coupled response to volcanic forcing. The core idea of VolMIP is to constrain radiative forcing among the participating models to focus on the climatic response, hence reference forcing dataare provided in terms of optical aerosol properties for a series of reference eruptions. * Zanchettin, D., O. Bothe, H. F. Graf, S. J. Lorenz, J. Luterbacher, C. Timmreck, and J. H. Jungclaus (2013) Background conditions influence the decadal climate response to strong volcanic eruptions. J. Geophys. Res. Atm., 118(10): 4090-4106, doi:10.1002/jgrd.50229, 10.1002/jgrd.50229 * This study illustrates how the decadal climate response to strong volcanic eruptions depends on the background climate state at the time of the eruption and on the presence and magnitude of additional external forcings acting at the same time. It demonstrates that background climate conditions are not merely a source of additive noise for post-eruption decadal climate variability but actively influence the mechanisms involved in the post-eruption decadal evolution. * Khodri M., Izumo T., Vialard J., Janicot S., Cassou C., Lengaigne M., Mignot J., Gastineau G., E. Guilyardi, Lebas N., Robock A. and M.J McPhaden, Tropical explosive volcanic eruptions can trigger El Niño by cooling tropical Africa, Nature Communications, 8, 778 (2017). , 10.1038/s41467-017-00755-6 * This paper presents new evidences for a possible interference of volcanic forcing from tropical stratospheric eruptions on ENSO cycle and discusses the underlying physical processes. Targeted climate model simulations emphasize that Pinatubo-like eruptions tend to shorten La Niñas, lengthen El Niños and induce anomalous warming when occurring during neutral states. It also presents a new mechanisms suggesting that volcanically induced cooling in tropical Africa weakens the West African monsoon, and the resulting atmospheric Kelvin wave can drive equatorial westerly wind anomalies over the western Pacific. This wind anomaly is further amplified by air-sea interactions in the Pacific, favouring an El Niño-like response. * Stoffel M, Khodri M., Corona C., Guillet S., Poulain V., Bekki S., Guiot J., Luckman B.H., Oppenheimer C., Lebas N., Beniston M.& Masson-Delmotte V., Reconciling reconstructions and simulations of volcanic cooling, Nature Geoscience, 8, 784-788 (2015), 10.1038/NGEO2526, 2015 * The climatic impact of the largest volcanic events has been assessed in numerous modelling studies and tree-ring-based hemispheric temperature reconstructions. However, volcanic surface cooling derived from PMIP3 climate model simulations is systematically much stronger than the cooling seen in tree-ring-based proxies, suggesting that the proxies underestimate cooling; and/or the modelled forcing is unrealistically high. This paper present a new summer temperature reconstructions for the Northern Hemisphere from tree-ring width and maximum latewood density over the past 1,500 years in comparison to simulated climate effects of two large eruptions, in AD 1257 and 1815, using a climate model that accounts explicitly for self-limiting aerosol microphysical processes. Results reveal for the first time an agreement between modelled and tree-ring based reconstruction of mean Northern Hemisphere extra-tropical summer cooling over land estimated between 0.8 to 1.3 degC for these eruptions. This reconciliation of proxy and model evidence paves the way to improved assessment of the role of both past and future volcanism in climate forcing. * Lora, J.M. (2018).Components and mechanisms of hydrologic cycle changes over North America at the Last Glacial Maximum. Journal of Climate 31, 7035-7051, https://doi.org/10.1175/JCLI-D-17-0544.1 * This paper provides a full moisture budget analysis of North America during the LGM, which gives context for and a comparison point for similar analyses of future hydroclimate changes. * Schenk F., Väliranta M., Muschitiello F., Tarasov L., Heikkilä M., Björck S., Brandefelt J., Johansson A.V., Näslund J.O., Wohlfarth B. (2018): Warm summers during the Younger Dryas cold reversal. Nat. Communications 9:1634, https://doi.org/10.1038/s41467-018-04071-5 * Very cold North Atlantic Ocean states in response to a weak AMOC cause persistent atmospheric blocking over Europe during summer. Proxy-model evidence suggests warmer and very dry conditions in response to a slowdown of the AMOC consistent with observations since the 1980s. * Emile-Geay, J., K. M. Cobb, M. Carre, P. Braconnot, J. Leloup, Y. Zhou, S. P. Harrison, T. Correge,H. V. McGregor, M. Collins, R. Driscoll, M. Elliot, B. Schneider, and A. Tudhope (2016), Links betweentropical pacific seasonal, interannual and orbital variability during the holocene, Nature Geosci, 9(2),168-173, 10.1038/ngeo2608 * This paper evaluates PMIP3 models and their ability to simulate the observed relationship between ENSO and the seasonal cycle on orbital scales. It reveals a fundamental discrepancy between models and observations that is critical to understanding the simulated ENSO response to future GHG emissions. * Ault, T. R., C. Deser, M. Newman, and J. Emile- Geay (2013), Characterizing decadal to centennial variability in the equatorial pacific during the last millennium, Geophysical Research Letters, 40, 3450-3456, 10.1002/grl.50647 * Evaluates the ability of PMIP3-CMIP5 models to simulate tropical Pacific variability over the past millennium, as reconstructed from proxy data. The article identifies important disagreements between simulations and reconstructions: in the models, variability primarily reflects a thermodynamic response to reconstructed solar and volcanic activity, whereas in the reconstruction, variability arises from either internal climate processes, forced responses that differ from those in CCSM4, or non-climatic proxy processes that are not yet understood. These findings imply that the response of the tropical Pacific to future forcings may be even more uncertain than portrayed by CMIP5 because there are potentially important sources of century-scale variability that these models do not simulate. * Luterbacher, J. and coauthors, 2016: European summer temperatures since Roman times. Environmental Research Letters, 11, 024001, doi:10.1088/1748-9326/11/2/024001 * A comparison with an ensemble of climate model simulations (PMIP5/CMIP3) suggests that the reconstructed European summer temperature variability over the period 850-2000CE reflects changes in both internal variability and external forcing on multi-decadal time-scales. * Lowry, D.P. and Morrill, C. 2018. Is the Last Glacial Maximum a reverse analog for future hydroclimate changes in the Americas? Climate Dynamics., 10.1007/s00382-018-4385-y * Future hydroclimate change is expected to generally follow a wet-get-wetter, dry-get-drier (WWDD) pattern, yet key uncertainties remain regionally and over land. We analyze 6 PMIP3 LGM simulations and show that, in some regions of North and South America, LGM hydroclimate changes could provide some insight into future changes in precipitation-evaporation. * Loomis, S.E., Russell, J.M., Verschuren, D., Morrill, C., De Cort, G., Sinninghe Damste, J.S., Olago, D., Eggermont, H., Street-Perrott, F.A., Kelly, M.A. 2017. The tropical lapse rate steepened during the Last Glacial Maximum. Science Advances 3: e1600815., 10.1126/sciadv.1600815 * A new 25,000-year temperature reconstruction from Mount Kenya, East Africa, demonstrates that cooling during the Last Glacial Maximum was amplified with elevation. Comparison of our data with PMIP3 LGM simulations indicates that state-of-the-art models underestimate this lapse-rate change. * Morrill, C., Lowry, D.P., Hoell, A. 2018. Thermodynamic and dynamic causes of pluvial conditions during the Last Glacial Maximum in Western North America. Geophysical Research Letters 45, 335-345., 10.1002/2017GL075807 * We analyze 9 PMIP3 simulations to argue that wet conditions in western North America at LGM were caused by a combination of dynamic and thermodynamic factors. These same factors, working in the opposite direction, are projected to cause regional drying in western North America under increased greenhouse gas concentrations, indicating continuity from past to future in the mechanisms altering hydroclimate. * Biasutti, M., Voigt, A., Boos, W. R., Braconnot, P., Hargreaves, J. C., Harrison, S. P., et al. (2018). Global energetics and local physics as drivers of past, present and future monsoons. Nature Geoscience, 11(6), 1-11. , http://doi.org/10.1038/s41561-018-0137-1 * Global constraints on momentum and energy govern the variability of the rainfall belt in the intertropical convergence zone and the structure of the zonal mean tropical circulation. * Hargreaves, J. C., & Annan, J. D. (2016). Could the Pliocene constrain the equilibrium climate sensitivity? Climate of the Past, 12(8), 1591-1599. , http://doi.org/10.5194/cp-12-1591-2016 * The mid-Pliocene Warm Period (mPWP) is the most recent interval in which atmospheric carbon dioxide was substantially higher than in modern pre-industrial times. Here we analyse results from the PlioMIP and, for the first time, discuss the potential for this interval to usefully constrain the equilibrium climate sensitivity. * Annan, J. D., & Hargreaves, J. C. (2015). A perspective on model-data surface temperature comparison at the Last Glacial Maximum. Quaternary Science Reviews, 107, 1-10. , http://doi.org/10.1016/j.quascirev.2014.09.019 * We review progress in model and proxy-based reconstruction of the surface temperature field of the Last Glacial Maximum. The magnitudes of the large-scale changes are increasingly well-constrained, with a recent model-data synthesis generating a value of 4 C, which suggests a moderate equilibrium climate sensitivity of about 2.5 C. * Harrison, S. P., Bartlein, P. J., Izumi, K., Li, G., Annan, J., Hargreaves, J., et al. (2015). Evaluation of CMIP5 palaeo-simulations to improve climate projections. Nature Climate Change, 5(8), 735-743. , http://doi.org/10.1038/nclimate2649 * Past climate changes provide a unique opportunity for out-of-sample evaluation of model performance. Palaeo-evaluation has shown that the large-scale changes seen in twenty-first-century projections, including enhanced land-sea temperature contrast, latitudinal amplification, changes in temperature seasonality and scaling of precipitation with temperature, are likely to be realistic. * Schmidt, G. A., Annan, J. D., Bartlein, P. J., Cook, B. I., Guilyardi, E., Hargreaves, J. C., et al. (2014). Using palaeo-climate comparisons to constrain future projections in CMIP5. Climate of the Past, 10(1), 221-250. , http://doi.org/10.5194/cp-10-221-2014 * Using palaeo-climate comparisons to constrain future projections! * Marzin, C., Kallel, N., Kageyama, M., Duplessy, J. C. and Braconnot, P. (2013). Glacial fluctuations of the Indian monsoon and their relationship with North Atlantic climate: new data and modelling experiments. Climate of the Past. 9: 2135-2151, https://doi.org/10.5194/cp-9-2135-2013 * This study analyse the processes that can explain the relationship between the Indian monsoon and the North Atlantic climate under glacial conditions, by increasing the freshwater flux in the North Atlantic and reducing the intensity of the Atlantic meridional overturning circulation. It shows that reduced indian monsoon is associated to changes in the continental runoff and local hydrological cycle that are responsible for the changes in salinity of the Bay of Bengal in the model. Sensitivity experiments also highlight that the changes over the tropical Atlantic are essential in triggering perturbations of the subtropical jet over Eurasia that in turn affect the intensity of the Indian monsoon. * Luan, Y. H., et al. (2015). "Tropical Pacific mean state and ENSO changes: sensitivity to freshwater flux and remnant ice sheets at 9.5 ka BP." Climate Dynamics 44(3-4): 661-678., https://doi.org/10.1007/s00382-015-2467-7 * Using as a reference a simulation of the early Holocene, the present study explores the relative contribution of ice-sheet and fresh water fluxes on themean climate state and ENSO variability in the tropical Pacific.The freshwater flux impact on ocean circulation and atmospheric feedbacks enhances ENSO amplitude. A feedback analysis suggests that it is due to the wind-thermocline feedback. The remnant ice sheett does not induce significant change in ENSO. Itexhibits a slight SST variability increase at the east coast and a reduction in the middle of the basin driven by the net. The freshwater flux forcing strengthens the amplitude of EP El Niño events. This mansucripts halp thus to unerstand the diversity of EL Niño event and the response of El Niño to external forcings. * Saint-Lu, M., et al. (2015). "Changes in the ENSO/SPCZ relationship from past to future climates." Earth and Planetary Science Letters 412: 18-24., http://doi.org/10.1016/j.epsl.2014.12.033 * This study considers a set of paleoclimate and future climate simulations. It shows that changes in the background tropical state largely control the mean SPCZ location. In contrast, changes in the background tropical state do not directly control the interannual variability of the SPCZ location. The relationship between ENSO and the SPCZ location varies from one climate to another. We thus demonstrate that the teleconnection mechanisms inferred from the modern climate cannot be directly extrapolated to other climates. This study therefore calls for a cautious interpretation of climate reconstructions from environmental indicators in the Southwest Pacific with regard to ENSO variations. * Blanchet, C. L., Contoux, C., Leduc, G.: Runoff and precipitation dynamics in the Blue and White Nile catchments during the mid-Holocene: a data-model comparison, Quaternary Science Reviews, 130, 222-230, doi: 10.1016/j.quascirev.2015.07.014, 2015., http://doi.org/10.1016/j.quascirev.2015.07.014 * This paper describes the changes in contribution between the White Nile and the Blue Nile river catchments during the mid-Holocene. By comparing regional proxy-records with the output from a global atmospheric model zoomed on Africa, we propose that the reduced contribution from the Blue Nile at 6 ka originated from both a higher White Nile runoff and a lower Blue Nile runoff. * Lunt, D. J., A. Abe-Ouchi, P. Bakker, A. Berger, P. Braconnot, S. Charbit, N. Fischer, N. Herold, J. H. Jungclaus, V. C. Khon, U. Krebs-Kanzow, P. M. Langebroek, G. Lohmann, K. H. Nisancioglu, B. Otto-Bliesner, W. Park, M. Pfeiffer, S. J. Phipps, M. Prange, R. Rachmayani, H. Renssen, N. Rosenbloom, B. Schneider, E. J. Stone, K. Takahashi, W. Wei, Q. Yin and Z. S. Zhang: A multi-model assessment of last interglacial temperatures, Climate of the Past, 9, 699-717, doi:10.5194/cp-9-699-2013, 2013., 10.5194/cp-9-699-2013 * Examines the PMIP3 simulations of the Last Interglacial and finds that the models do not agree well with reconstructions. In particular, the models fail to replicate the reconstructed warming at high latitudes. * Bakker, P., V. Masson-Delmotte, B. Martrat, S. Charbit, H. Renssen, M. Gröger, U. Krebs-Kanzow, G. Lohman, D. J. Lunt, M. Pfeiffer, S. J. Phipps, M. Prange, S. P. Ritz, M. Schulz, B. Stenni, E. J. Stone and V. Varma: Temperature trends during the Present and Last Interglacial periods - a multi-model-data comparison, Quaternary Science Reviews, 99, 224-243, doi:10.1016/j.quascirev.2014.06.031, 2014., 10.1016/j.quascirev.2014.06.031 * The reconstructed Present Interglacial (PIG) and Last Interglacial (LIG) Northern Hemisphere mid-to-high latitude cooling compares well with multi-model, mean temperature trends for the warmest months and that these cooling trends reflect a linear response to the warmest-month insolation decrease over the interglacial intervals. The most notable exception is the strong LIG cooling trend reconstructed from Greenland ice cores that is not simulated by any of the models. A striking model-data mismatch is found for both the PIG and the LIG over large parts of the mid-to-high latitudes of the Southern Hemisphere where the data depicts negative temperature trends that are not in agreement with near zero trends in the simulations. * Abram, N. J., H. V. McGregor, J. E. Tierney, M. N. Evans, N. P. McKay, D. S. Kaufman and the PAGES 2k Consortium (K. Thirumalai, B. Martrat, H. Goosse, S. J. Phipps, E. J. Steig, K. Halimeda Kilbourne, C. P. Saenger, J. Zinke, G. Leduc, J. A. Addison, P. Graham Mortyn, M.-S. Seidenkrantz, M.-A. Sicre, K. Selvaraj, H. L. Filipsson, R. Neukom, J. Gergis, M. A. J. Curran and L. von Gunten): Early onset of industrial-era warming across the oceans and continents, Nature, 536, 411-418, doi:10.1038/nature19082, 2016., 10.1038/nature19082 * Here we use post AD 1500 palaeoclimate records to show that sustained industrial-era warming of the tropical oceans first developed during the mid-nineteenth century and was nearly synchronous with Northern Hemisphere continental warming. The early onset of sustained, significant warming in palaeoclimate records and model simulations suggests that greenhouse forcing of industrial-era warming commenced as early as the mid-nineteenth century and included an enhanced equatorial ocean response mechanism. The development of Southern Hemisphere warming is delayed in reconstructions, but this apparent delay is not reproduced in climate simulations. Our findings imply that instrumental records are too short to comprehensively assess anthropogenic climate change and that, in some regions, about 180 years of industrial-era warming has already caused surface temperatures to emerge above pre-industrial values, even when taking natural variability into account. * Ackerley, D., J. Reeves, C. Barr, H. Bostock, K. Fitzsimmons, M.-S. Fletcher, C. Gouramanis, H. McGregor, S. Mooney, S. J. Phipps, J. Tibby and J. Tyler: Evaluation of PMIP2 and PMIP3 simulations of mid-Holocene climate in the Indo-Pacific, Australasian and Southern Ocean regions, Climate of the Past, 13, 1661-1684, doi:10.5194/cp-13-1661-2017, 2017., 10.5194/cp-13-1661-2017 * Shows that the PMIP2/PMIP3 models and proxies agree on the differences in climate state for 6 ka relative to 0 ka, when they are insolation driven. The largest uncertainty between the models and the proxies occurs over the Indo-Pacific Warm Pool (IPWP). * PAGES Hydro2k Consortium (J. E. Smerdon, J. Luterbacher, S. J. Phipps, K. J. Anchukaitis, T. Ault, S. Coats, K. M. Cobb, B. I. Cook, C. Colose, T. Felis, A. Gallant, J. H. Jungclaus, B. Konecky, A. LeGrande, S. Lewis, A. S. Lopatka, W. Man, J. S. Mankin, J. T. Maxwell, B. L. Otto-Bliesner, J. W. Partin, D. Singh, N. J. Steiger, S. Stevenson, J. E. Tierney, D. Zanchettin, H. Zhang, A. R. Atwood, L. Andreu-Hayles, S. H. Baek, B. Buckley, E. R. Cook, R. D'Arrigo, S. G. Dee, M. L. Griffiths, C. Kulkarni, Y. Kushnir, F. Lehner, C. Leland, H. W. Linderholm, A. Okazaki, J. Palmer, E. Piovano, C. C. Raible, M. P. Rao, J. Scheff, G. A. Schmidt, R. Seager, M. Widmann, A. P. Williams and E. Xoplaki): Comparing proxy and model estimates of hydroclimate variability and change over the Common Era, Climate of the Past, 13, 1851-1900, doi:10.5194/cp-13-1851-2017, 2017., 10.5194/cp-13-1851-2017 * We review the principal proxy data available for hydroclimatic reconstructionsover the Common Era (CE) and highlight the contemporary understanding of how these proxies are interpreted as hydroclimate indicators. We also review the available last-millennium simulations from fully coupled climate models and discuss several outstanding challenges associated with simulating hydroclimate variability and change over the CE. * Meyer, H., Opel, T., Laepple, T., Dereviagin, A. Y., Hoffmann, K. and Werner, M.: Long-term winter warming trend in the Siberian Arctic during the mid- to late Holocene, Nature Geoscience, 8(2), 122-125, doi:10.1038/ngeo2349, 2015., 10.1038/ngeo2349 * The paper presents a record of the oxygen isotope composition of permafrost ice wedges from the Siberian Arctic. In agreement with most PIMP3 models, the record shows a winter warming trend during the mid- to late Holocene, opposing the cooling seen in other proxy records. * Stenni, B., Curran, M. A. J., Abram, N. J., Orsi, A., Goursaud, S., Masson-Delmotte, V., Neukom, R., Goosse, H., Divine, D., Ommen, T. V., Steig, E. J., Dixon, D. A., Thomas, E. R., Bertler, N. A. N., Isaksson, E., Ekaykin, A., Werner, M. and Frezzotti, M.: Antarctic climate variability on regional and continental scales over the last 2000 years, Clim. Past, 13(11), 1609-1634, doi:10.5194/cp-13-1609-2017, 2017., 10.5194/cp-13-1609-2017 * The paper presents a most recent compilation of water stable isotope records from Antarctica, analysing climate variability on regional and continental scales over the last 2000 years. It shows that only for the Antarctic Peninsula the most recent century-scale warming trend is unusual in the context of natural variability over the last 2000 years. * Werner, M., Jouzel, J., Masson-Delmotte, V. and Lohmann, G.: Reconciling glacial Antarctic water stable isotopes with ice sheet topography and the isotopic paleothermometer, Nature Communications, 9(1), 3537, doi:10.1038/s41467-018-05430-y, 2018., 10.1038/s41467-018-05430-y * The study compares different glacial maximum ice sheet reconstructions of Antarctica by using an isotope-enabled high-resolution atmosphere GCM. A best model data match is achieved for the PMIP3 reconstruction. Furthermore, the performed modern and glacial climate simulations support the validity of the isotopic paleothermometer approach based on the use of present-day observations. * Bartlein, P.J., S.P. Harrison and K. Izumi, 2017, Underlying causes of Eurasian mid-continental aridity in simulations of mid-Holocene climate, Geophysical Research Letters. 44:1-9, http://dx.doi.org/10.1002/2017GL074476 * Discusses a long-standing mismatch between climate-model simulations and paleo observations and relates these to present-day biases in atmospheric circulation and moisture flux * Emile-Geay, J., Cobb, K.M., Carré, M., Braconnot, P., Leloup, J., Zhou, Y., Harrison, S.P., Corrège, T., Collins, M., Driscoll, R., Elliot, M., McGregor, H.V., Schneider, B., Tudhope, A., 2015. Linkages between tropical Pacific seasonal, interannual and orbital variability during the Holocene. Nature Geoscience 9: 168-173. doi:10.1038/ngeo2608, doi:10.1038/ngeo2608 * Shows that ENSO variance was reduced throughout most of the Holocene and that this quiescence is not obvioulsy related to orbital forcing. Climate models are unable to reproduce these observations. * Perez-Sanz, A., Li, G., Gonzalez, P., Harrison, S.P., 2014. Evaluation of seasonal climates of northern Africa and the Mediterranean in the CMIP5 simulations. Climate of the Past 10: 551-568. doi:10.5194/cp-10-551-2014, doi:10.5194/cp-10-551-2014 * Provides an evaluation of the ability of the CMIP5 simulations to simukate enhanced monsoons during the mid-Holocene. * Luo, X. and Wang, B., 2018. How autumn Eurasian snow anomalies affect east asian winter monsoon: a numerical study. Climate Dynamics, pp.1-14., https://doi.org/10.1007/s00382-018-4138-y * The possible mechanisms by which Eurasian autumn snow anomalies affect east asian winter monsoon (EAWM) are investigated by numerical experiments with a coupled general circulation model and its atmospheric general circulation model component. Mongolian Plateau and Vicinity (MPV, 40°-55°N, 80°-120°E) is the key region for autumn snow anomalies to affect EAWM, and snow anomalies over the MPV region can affect EAWM through a positive feedback process. * Prado, L. F., Wainer, I., Chiessi, C. M. (2013). Mid-Holocene PMIP3/CMIP5 model results: Intercomparison for the South American Monsoon System. The Holocene, Vol 23, Issue 12, 1915-1920., 10.1177/0959683613505336 * This paper contains an unpdated proxy compilation for South American Monsoon System during the Mid-Holocene, and also a data-model comparison using the PMIP3 models. * Oster, J. L., Ibarra, D. E., Winnick, M. J., & Maher, K. (2015). Steering of westerly storms over western North America at the Last Glacial Maximum. Nature Geoscience, 8(3), 201., 10.1038/ngeo2365 * Evaluation of model (PMIP3/PMIP2) performance using paleoclimate data, constraints on precipitation change caused be climate forcing and P-E changes observed using paleoclimate records. * Ibarra, D. E., Oster, J. L., Winnick, M. J., Caves Rugenstein, J. K., Byrne, M. P., & Chamberlain, C. P. (2018). Warm and cold wet states in the western United States during the Pliocene-Pleistocene. Geology, 46(4), 355-358., 10.1130/G39962.1 * Water cycle and regional moisture energy balance budget change constrained by geologic/paleoclimate data and PMIP models in semi-arid region. * R D'Agostino, J Bader, S Bordoni, D Ferreira, J Jungclaus (2019): Northern Hemisphere Monsoon Response to Mid-Holocene Orbital Forcing and Greenhouse Gas-Induced Global Warming, Geophysical Research Letters 46 (3), 1591-1601, https://doi.org/10.1029/2018GL081589 * Mechanisms driving monsoon response to midHolocene orbital forcing and rcp8.5 greenhouse-induced global warming scenario are different. A decomposition of the moisture budget in thermodynamic and dynamic contributions suggests that under future global warming, the weaker response of the African, Indian, and North American monsoons results from a compensation between both components. The dynamic component, primarily constrained by changes in net energy input over land, determines instead most of the mid-Holocene land monsoonal rainfall response. This process-oriented study takes an important step toward improving our understanding of monsoon dynamics, quantifying the important role of atmospheric circulation changes in monsoonal precipitation changes by comparing and contrasting past and future climates. Our results highlight that mean surface warming and interhemispheric contrast in surface warming are poor indicators of the monsoonal precipitation response. Rather, the monsoon response is constrained by the integrated energy balance, which accounts for changes at the surface as well as at the top of the atmosphere. This explains why the mid-Holocene does not represent an analogue for future warming. * Sánchez-Goñi, M.F., Bard, E., Landais, A., Rossignol, L., d'Errico, F. (2013). Air-sea temperature decoupling in Western Europe during the last interglacial/glacial transition. Nature Geoscience 6 , 837-841, DOI : 10.1038/ngeo1924 * In contrast with periods of relatively stable global ice volume (e.g. present-day interglacial), periods of ice-sheet growth are marked by a decoupling between eastern North Atlantic warming and European cooling. This configuration allows a northward shift of the westerlies bringing humidity to the high northern latitudes. * Zorzi, C., Sánchez Goñi, M.F., Anupama, K., Prasad, S., Hanquiez, V., Johnson, J., Giosan, L. (2015) Indian monsoon variations during three contrasting climatic periods: the Holocene, HeinrichStadial 2 and the last interglacial-glacial transition. Quaternary Science Reviews 125, 50-60., doi.org/10.1016/j.quascirev.2015.06.009 * Insolation changes control the long term trend of the Indian monsoon precipitation, but its millennial scale variability and intensity are instead modulated by atmospheric teleconnections to remote phenomena in the North Atlantic (e.g. amount of sea-ice or iceberg discharges), Eurasia or the Indian Ocean. * Sánchez Goñi, M.F., Rodrigues, T., Hodell, D.A., Polanco-Martinez, J.M., Alonso-Garcia, M., Hernandez-Almeida, I., Desprat, S., Ferretti, P. (2016) Tropically-driven climate shifts in southwestern Europe during MIS 19, a low excentricity interglacial. Earth and Planetary Science Letters 448, 81-93., http://dx.doi.org/10.1016/j.epsl.2016.05.018 * MIS 19, the best orbital analogue to our present interglacial, is marked by low latitude-driven 5000-yr cycles of drying and cooling in the western Mediterranean region, along with warmth in the subtropical gyre related to the fourth harmonic of precession. The discrepancy between the dominant cyclicity observed during MIS1, 2500-yr, and that of MIS19, 5000-yr, challenges the similar duration of the Holocene and MIS19c interglacials under natural boundary conditions. * Oliveira, D., Desprat, S., Yin, Q., Naughton, F., Trigo, R., Rodrigues, T., Abrantes, F., Sánchez Goñi, M.F. (2018). Unraveling the forcings controlling the vegetation and climate of the best orbital analogues for the present interglacial in SW Europe. Climate Dynamics 51, 667-686, doi:10.1007/s00382-017-3948-7 * Data-model comparison reveals that the SW Iberian forest dynamics over the best orbital analogues to our present interglacial are mostly coupled to changes in winter precipitation mainly controlled by precession, CO2 playing a negligible role. In contrast, the reconstructed lower forest optimum at MIS 19c is not reproduced by the simulations probably due to the lack of Eurasian ice sheets and its related feedbacks in the model. * Sánchez Goñi, M.F., Ferretti, P., Polanco-Martinez, J.M., Rodrigues, T., Alonso-Garcia, M., Rodriguez-Tovar, F.J., Dorador, J., Desprat, S. (2019). Pronounced northward shift of the westerlies during MIS 17 leading to the strong 100-kyr ice age cycles. Earth and Planetary Science Letters 511, 117-129., https://doi.org/10.1016/j.epsl.2019.01.032. * During MIS 17 (700 ka), a cold interglacial characterized by the lowest atmospheric CO2 concentrations of the last 800,000 years, the Iberian Peninsula was paradoxically marked by the maximum in the Mediterranean forest expansion indicating strong winter precipitation and summer warmth. These data indicate a decoupling between global and regional climates. This work also highlights the important contribution of the westerlies leading to the strong 100-kyr ice age cycles. These atmospheric changes remain, however, a key area of uncertainty in past and future climate model simulations. * Sánchez Goñi, M.F., Desprat, S., Daniau, A.-L., Bassinot, F., Polanco-Martinez, J.M., Harrison, S.P. and ACER contributors (2017). The ACER pollen and charcoal database : a global resource to document vegetation and fire response to abrupt climate changes during the last glacial period. Earth System Science Data, 9, 679-695., https://doi.org/10.5194/essd-9-679-2017 * This global vegetation and fire data compilation shows the regional response to rapid past climate changes comparable in velocity and magnitude to those expected in the 21st-century. * A.Kislov. On the interpretation of century-millennium-scale variations of the Black Sea level during the first quarter of the Holocene. Quaternary International. Volume 465, Part A, 2018, Pages 99-104., https://doi.org/10.1016/j.quaint.2016.09.008 * model-data, and data syntheses * Kislov A. The interpretation of secular Caspian Sea level records during the Holocene Quaternary International, 2016, vol. 409, 39-43 , https://doi.org/10.1016/j.quaint.2015.07.026 * data syntheses : * Yanko-Hombach, V., Kislov, A., Late Pleistocene and Holocene sea-level dynamics in the Caspian and Black Seas: Data synthesis and Paradoxical interpretations, Quaternary International (2017) , https://doi.org/10.1016/j.quaint.2017.11.030 * model-data, and data syntheses * Kislov A. 2018 Secular Variability of the Caspian Sea Level. Russian Meteorology and Hydrology, vol. 43, No 10, 679-685 , 10.3103/S1068373918100072 * data syntheses ===== Chapter 11: Weather and Climate Extreme Events in a Changing Climate ===== Number of selected references: **13** * Stevenson, S, J. Overpeck, J. T. Fasullo, S. Coats, L. Parsons, B. Otto-Bliesner, T. R. Ault, G. Loope, J. Cole, 2018: Climate Variability, Volcanic Forcing, and Last Millennium Climate Extremes, Journal of Climate, 31, 4309-4327., n/a * The Community Earth System Model (CESM) Last Millennium Ensemble to examine statistical associations between regional mega-events (megadroughts and megapluvials), coupled climate modes, forcing from major volcanic eruptions. * Polanski, S., B. Fallah, D. J. Befort, S. Prasad and U. Cubasch, 2014: Regional moisture change over India during the past Millenium: A comparison of multi-proxy reconstructions and climate model simulations. Global and Planetary Change, 122, 176-185, , dx.doi.org.10.1016/J.gloplacha.2014.08.016 * regional moisture variability during the past millennium over India * Fallah, B. and U. Cubasch, 2015: A comparison of model simulations of Asian mega-droughts during the past millennium with proxy reconstructions, Clim. Past, 11, 253-263, doi:10.5194/cp-11-253-2015 * Analysis of mega droughts in models and observational (proxy) data during the last millennium * Fallah, B, S. Sodoudi and U. Cubasch, 2015: Westerly jet stream and past millenium climate change in Arid Central Asia simulated by COSMO-CLM model. , DOI 10.1007/s00704-015-1479-x * natural regional climate variability and extremes * Bo Huang, S. Polanski and U. Cubasch, 2015: Assessment of precipitation climatology in an ensemble of CORDEX-East Asia regional climate simulations. Clim Res Vol. 64: 141-158, doi: 10.3354/cr01302 * precipitation climatology of models in CORDEX East Asia region * Otto-Bliesner, B.L. et al., 2017: The PMIP4 contribution to CMIP6 - Part 2: Two interglacials, Scientific objectives and experimental design of the PMIP4-CMIP6 Holocene and Last Interglacial simulations. Geoscientific Model Development, 10, 3979-4003, doi:10.5194/cp-12-1645-2016 * regional temperature evolution over Europe during the Holocene * Schenk F., Väliranta M., Muschitiello F., Tarasov L., Heikkilä M., Björck S., Brandefelt J., Johansson A.V., Näslund J.O., Wohlfarth B. (2018): Warm summers during the Younger Dryas cold reversal. Nat. Communications 9:1634, https://doi.org/10.1038/s41467-018-04071-5 * Very cold North Atlantic Ocean states in response to a weak AMOC cause persistent atmospheric blocking over Europe during summer. Proxy-model evidence suggests warmer and very dry conditions in response to a slowdown of the AMOC consistent with observations since the 1980s. * Hakim, G. J., J. Emile-Geay, E. J. Steig, D. Noone, D. M. Anderson, R. Tardif, N. Steiger, and W. A. Perkins (2016), The last millennium climate reanalysis project: Framework and first results, Journal of Geophysical Research: Atmospheres, 121, 6745 - 6764, 10.1002/2016JD024751 * Provides the first validated, global, multivariate reconstruction of climate fields based on a fusion of proxy and GCM runs. * Biasutti, M., Voigt, A., Boos, W. R., Braconnot, P., Hargreaves, J. C., Harrison, S. P., et al. (2018). Global energetics and local physics as drivers of past, present and future monsoons. Nature Geoscience, 11(6), 1-11. , http://doi.org/10.1038/s41561-018-0137-1 * Global constraints on momentum and energy govern the variability of the rainfall belt in the intertropical convergence zone and the structure of the zonal mean tropical circulation. * PAGES Hydro2k Consortium (J. E. Smerdon, J. Luterbacher, S. J. Phipps, K. J. Anchukaitis, T. Ault, S. Coats, K. M. Cobb, B. I. Cook, C. Colose, T. Felis, A. Gallant, J. H. Jungclaus, B. Konecky, A. LeGrande, S. Lewis, A. S. Lopatka, W. Man, J. S. Mankin, J. T. Maxwell, B. L. Otto-Bliesner, J. W. Partin, D. Singh, N. J. Steiger, S. Stevenson, J. E. Tierney, D. Zanchettin, H. Zhang, A. R. Atwood, L. Andreu-Hayles, S. H. Baek, B. Buckley, E. R. Cook, R. D'Arrigo, S. G. Dee, M. L. Griffiths, C. Kulkarni, Y. Kushnir, F. Lehner, C. Leland, H. W. Linderholm, A. Okazaki, J. Palmer, E. Piovano, C. C. Raible, M. P. Rao, J. Scheff, G. A. Schmidt, R. Seager, M. Widmann, A. P. Williams and E. Xoplaki): Comparing proxy and model estimates of hydroclimate variability and change over the Common Era, Climate of the Past, 13, 1851-1900, doi:10.5194/cp-13-1851-2017, 2017., 10.5194/cp-13-1851-2017 * We review the principal proxy data available for hydroclimatic reconstructionsover the Common Era (CE) and highlight the contemporary understanding of how these proxies are interpreted as hydroclimate indicators. We also review the available last-millennium simulations from fully coupled climate models and discuss several outstanding challenges associated with simulating hydroclimate variability and change over the CE. * Luo, X. and Wang, B., 2017. How predictable is the winter extremely cold days over temperate East Asia?. Climate dynamics, 48(7-8), pp.2557-2568., https://doi.org/10.1007/s00382-016-3222-4 * This work estimates the NECD predictability in temperate East Asia(TEA, 30°-50°N, 110°-140°E) where the current dynamical models exhibit limited prediction skill. We used physics-based empirical models (PEMs) to explore the sources and limits of the seasonal predictability in the winter extremely cold days over over TEA. * Luo, X. and Wang, B., 2018. Predictability and prediction of the total number of winter extremely cold days over China. Climate Dynamics, 50(5-6), pp.1769-1784., https://doi.org/10.1007/s00382-017-3720-z * The present study uses physics-based empirical models (PEMs) to explore the sources and limits of the seasonal predictability in the total number of extremely cold days (NECD) over China.The physical mechanisms by which the autumn Arctic sea ice, snow cover, and tropical- North Pacific SST anomalies affect winter NECD over the Northeast and Main China are discussed. * Morrill, C., Meador, E., Livneh, B., Liefert, D.T., Shuman, B.N. 2019. Quantitative model-data comparison of mid-Holocene lake-level change in the central Rocky Mountains. Climate Dynamics. , 10.1007/s00382-019-04633-3 * We used several hydrologic forward models in a form of downscaling to quantitatively compare PMIP3 simulations with lake level records. We found that the severity of mid-Holocene drought in western/central North America about 6,000 years ago is consistent with local winter precipitation reductions of up to 50%, and that PMIP3 models fail to reproduce the severity of this drought. ===== Chapter 12: Climate change information for regional impacts and risk assessment ===== Number of selected references: **15** * Mares, C., I. Mares, H. Huebener, M. Mihailescu, U. Cubasch, and P. Stanciu, 2014: A Hidden Markov Model Applied to the Daily Spring Precipitation over the Danube Basin. Advances in Meteorology, Volume 2014 (2014), Article ID 237247, 11 pp, dx.doi.org/10.1155/2014/237247 * Regional derivation of daily spring precipitation * Polanski, S., B. Fallah, D. J. Befort, S. Prasad and U. Cubasch, 2014: Regional moisture change over India during the past Millenium: A comparison of multi-proxy reconstructions and climate model simulations. Global and Planetary Change, 122, 176-185, , dx.doi.org.10.1016/J.gloplacha.2014.08.016 * regional moisture variability during the past millennium over India * Sommerfeld, A., K. Prömmel and U. Cubasch, 2014: The East African Rift System and the impact of orographic changes on regional climate and the resulting aridification. Int. J. Earth Sci, , DOI 10.1007.200531-014-1102-x * regional orographic effects on the hydrological cycle * Bo Huang, S. Polanski and U. Cubasch, 2015: Assessment of precipitation climatology in an ensemble of CORDEX-East Asia regional climate simulations. Clim Res Vol. 64: 141-158, doi: 10.3354/cr01302 * precipitation climatology of models in CORDEX East Asia region * Befort, D. J., G. C. Leckebusch and U. Cubasch, 2016: Intraseasonal variability of the Indian summer monsoon: wet and dry events in COSMO-CLM. , DOI 10.1007/s00382-016-2989-7 * intraseasonal variability of Indian summer monsoon in regional model simulation * Xiaoli Chi, Rui Li, Ulrich Cubasch and Wenting Cao, 2017: The thermal comfort and its changes in the 31 provincial capital cities of mainland China in the past 30 years, Theoretical and Applied Climatology, 1-21, 10.1007/s00704-017-2099-4 * regional impact of climate change * Bo Huang, Ulrich Cubasch and Yan Li, 2018: East-Asian Summer Monsoon Representation in Re-Analysis Datasets. Atmosphere, 9, 235, , doi:10.3390/atmos9060235 * Evaluation of the description of the regional variability in different re-analysis Dara sets * Lambert, F., J.-S. Kug, R. J. Park, N. Mahowald, G. Winckler, A. Abe-Ouchi, R. O'ishi, T. Takemura, and J.-H. Lee (2013), The role of mineral-dust aerosols in polar temperature amplification, Nat. Clim. Chang., 3(5), 487-491, 10.1038/nclimate1785 * Impact of high atmospheric dust loads on polar temperature * Loomis, S.E., Russell, J.M., Verschuren, D., Morrill, C., De Cort, G., Sinninghe Damste, J.S., Olago, D., Eggermont, H., Street-Perrott, F.A., Kelly, M.A. 2017. The tropical lapse rate steepened during the Last Glacial Maximum. Science Advances 3: e1600815., 10.1126/sciadv.1600815 * A new 25,000-year temperature reconstruction from Mount Kenya, East Africa, demonstrates that cooling during the Last Glacial Maximum was amplified with elevation. Comparison of our data with PMIP3 LGM simulations indicates that state-of-the-art models underestimate this lapse-rate change. * Biasutti, M., Voigt, A., Boos, W. R., Braconnot, P., Hargreaves, J. C., Harrison, S. P., et al. (2018). Global energetics and local physics as drivers of past, present and future monsoons. Nature Geoscience, 11(6), 1-11. , http://doi.org/10.1038/s41561-018-0137-1 * Global constraints on momentum and energy govern the variability of the rainfall belt in the intertropical convergence zone and the structure of the zonal mean tropical circulation. * PAGES Hydro2k Consortium (J. E. Smerdon, J. Luterbacher, S. J. Phipps, K. J. Anchukaitis, T. Ault, S. Coats, K. M. Cobb, B. I. Cook, C. Colose, T. Felis, A. Gallant, J. H. Jungclaus, B. Konecky, A. LeGrande, S. Lewis, A. S. Lopatka, W. Man, J. S. Mankin, J. T. Maxwell, B. L. Otto-Bliesner, J. W. Partin, D. Singh, N. J. Steiger, S. Stevenson, J. E. Tierney, D. Zanchettin, H. Zhang, A. R. Atwood, L. Andreu-Hayles, S. H. Baek, B. Buckley, E. R. Cook, R. D'Arrigo, S. G. Dee, M. L. Griffiths, C. Kulkarni, Y. Kushnir, F. Lehner, C. Leland, H. W. Linderholm, A. Okazaki, J. Palmer, E. Piovano, C. C. Raible, M. P. Rao, J. Scheff, G. A. Schmidt, R. Seager, M. Widmann, A. P. Williams and E. Xoplaki): Comparing proxy and model estimates of hydroclimate variability and change over the Common Era, Climate of the Past, 13, 1851-1900, doi:10.5194/cp-13-1851-2017, 2017., 10.5194/cp-13-1851-2017 * We review the principal proxy data available for hydroclimatic reconstructionsover the Common Era (CE) and highlight the contemporary understanding of how these proxies are interpreted as hydroclimate indicators. We also review the available last-millennium simulations from fully coupled climate models and discuss several outstanding challenges associated with simulating hydroclimate variability and change over the CE. * Martin Calvo, M., Prentice, I.C., Harrison, S.P., 2014. Climate versus carbon dioxide controls on biomass burning: a model analysis of the glacial-interglacial contrast. Biogeosciences, 11, 6017-6027. doi:10.5194/bg-11-6017-2014, doi:10.5194/bg-11-6017-2014a * Demonstrates that changing CO2 since the Last Glacial Maximum has affected fire regimes through altering productivity and hence fuel loads. By analogy, both rising CO2 and climate must be considered as risk factors for wildfire. * Morrill, C., Meador, E., Livneh, B., Liefert, D.T., Shuman, B.N. 2019. Quantitative model-data comparison of mid-Holocene lake-level change in the central Rocky Mountains. Climate Dynamics. , 10.1007/s00382-019-04633-3 * We used several hydrologic forward models in a form of downscaling to quantitatively compare PMIP3 simulations with lake level records. We found that the severity of mid-Holocene drought in western/central North America about 6,000 years ago is consistent with local winter precipitation reductions of up to 50%, and that PMIP3 models fail to reproduce the severity of this drought. * Oliveira, D., Desprat, S., Yin, Q., Naughton, F., Trigo, R., Rodrigues, T., Abrantes, F., Sánchez Goñi, M.F. (2018). Unraveling the forcings controlling the vegetation and climate of the best orbital analogues for the present interglacial in SW Europe. Climate Dynamics 51, 667-686, doi:10.1007/s00382-017-3948-7 * Data-model comparison reveals that the SW Iberian forest dynamics over the best orbital analogues to our present interglacial are mostly coupled to changes in winter precipitation mainly controlled by precession, CO2 playing a negligible role. In contrast, the reconstructed lower forest optimum at MIS 19c is not reproduced by the simulations probably due to the lack of Eurasian ice sheets and its related feedbacks in the model. * Sánchez Goñi, M.F., Desprat, S., Daniau, A.-L., Bassinot, F., Polanco-Martinez, J.M., Harrison, S.P. and ACER contributors (2017). The ACER pollen and charcoal database : a global resource to document vegetation and fire response to abrupt climate changes during the last glacial period. Earth System Science Data, 9, 679-695., https://doi.org/10.5194/essd-9-679-2017 * This global vegetation and fire data compilation shows the regional response to rapid past climate changes comparable in velocity and magnitude to those expected in the 21st-century. pubs/chaptersar6.txt Last modified: 2019/08/28 09:03by jypeter