exp_design:degla_t2 [PMIP4]

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====== Design for the Penultimate Deglaciation experiment ======

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You will find on this page information about the experiment design for the PMIP4 [[exp_design:degla_t2|Penultimate Deglaciation]] experiments.

This protocol is a product of the //PAGES-PMIP working group on Quaternary Interglacials// ([[http://pastglobalchanges.org/ini/wg/quigs/intro|QUIGS]])

Please make sure to read the [[#Associated_publications|Associated publications]] before setting up your experiments or using the output data, and read any //how-to// sections associated with specific boundary conditions.

Get in touch with the following people if you have questions:

| [[l.menviel@unsw.edu.au|Laurie Menviel]] | Experimental design questions |
| [[capron@nbi.ku.dk|Emilie Capron]] | Experimental design questions |
| [[R.Ivanovic@leeds.ac.uk|Ruza Ivanovic]] | working group leader |
| [[Jean-Yves.Peterschmitt@lsce.ipsl.fr|Jean-Yves Peterschmitt]] | Technical questions or missing data |
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==== Associated publications ====

  * **Penultimate Deglaciation experiment design, version 1:**\\ \\ **The penultimate deglaciation: protocol for Paleoclimate Modelling Intercomparison Project (PMIP) phase 4 transient numerical simulations between 140 and 127 ka, version 1.0**, Menviel, L., Capron, E., Govin, A., Dutton, A., Tarasov, L., Abe-Ouchi, A., Drysdale, R. N., Gibbard, P. L., Gregoire, L., He, F., Ivanovic, R. F., Kageyama, M., Kawamura, K., Landais, A., Otto-Bliesner, B. L., Oyabu, I., Tzedakis, P. C., Wolff, E., and Zhang, X., Geosci. Model Dev., 12, 3649-3685, [[https://doi.org/10.5194/gmd-12-3649-2019|doi:10.5194/gmd-12-3649-2019]], 2019\\ \\ [[https://www.geosci-model-dev.net/12/3649/2019/gmd-12-3649-2019-supplement.zip|Supplement (Menviel et al, GMD, 2019)]]

===== Version 1 Specifications =====

For general advice on boundary condition implementation in palaeoclimate models, see [[#References_cited|Kageyama et al. (2016)]].

==== Penultimate Glacial Maximum spinup (140 ka) ====

If possible, this spinup simulation should start from the PMIP4-CMIP6 LGM (21 ka) experiment, as equilibrium would be reached more quickly.

^      ^PMIP4 specifications ^ 
| PMIP4 name | <wrap em>PDGv1-PGMspin</wrap> (''PDG'' <=> //**P**enultimate **D**e**G**laciation// - ''PGM'' <=> //**P**enultimate **G**lacial **M**aximum//) |
| Astronomical parameters  | **eccentricity** = 0.033 \\ **obliquity** = 23.414° \\  **perihelion-180°** = 73°  \\  **Date of vernal equinox**  :  Noon, 21st March  |  
| Solar constant | 1361.0 ± 0.51365 W m<sup>-2</sup>  | 
| Trace gases  | **CO<sub>2</sub>** = 191 ppm \\ **CH<sub>4</sub>** = 385 ppb \\ **N<sub>2</sub>O** = 201 ppb \\ **CFC** = 0 \\ **O<sub>3</sub>** = Preindustrial (e.g. 10 DU)  | 
| Ice sheets, orography \\ and coastlines  | 140 ka data from Combined ice-sheet reconstruction (IcIES-NH, GSM-G and GSM-A): [ [[:data:ice_glac_1d|Access to data]] ]\\ (Abe-Ouchi et al 2013; Briggs et al 2014; Tarasov et al 2012) | 
| Bathymetry  | Keep consistent with the coastlines, using either: \\ - Data associated with the ice sheet \\ - Preindustrial bathymetry | 
| Global ocean salinity | + 0.85 psu, relative to preindustrial  |
| All others  | See manuscript section 6.1 | 

==== Transient Penultimate Deglaciation (140-127 ka) ====

These are the specifications for the full transient run 140-127 ka.

^      ^PMIP4 specifications ^ 
| PMIP4 name | <wrap em>PDGv1</wrap> |
| Initial conditions (140 ka) | Recommended: PDGv1-PGMspin \\ See above for details. The method must be documented, including information on the state of spinup  |  
| Astronomical parameters  | Transient, as per [[#References_cited|Berger (1978)]]\\ [ [[ftp://ftp.ncdc.noaa.gov/pub/data/paleo/climate_forcing/orbital_variations/insolation//bein1.dat|Access to data]] **&** [[ftp://ftp.ncdc.noaa.gov/pub/data/paleo/climate_forcing/orbital_variations/insolation//readme_insolation.txt|README !]] ] (''md5sum bein1.dat'' => ''726dfae36b33ae248bdb94f59387a19f'') |  
| Solar constant | 1361.0 ± 0.51365 W m<sup>-2</sup>  | 
| Trace gases  | **CO<sub>2</sub>** = Transient, as per [[#References_cited| the spline of Koehler et al. (2017)]]: [ [[https://doi.pangaea.de/10.1594/PANGAEA.871273|Access to data]] ] \\ **CH<sub>4</sub>** = Transient, as per [[#References_cited| the spline of Koehler et al. (2017)]]: [ [[https://doi.pangaea.de/10.1594/PANGAEA.871273|Access to data]] ] \\ **N<sub>2</sub>O** = Linear increase from 201 ppb at 140 ka to 218.74 ppb at 134.5 ka\\ then transient, as per [[#References_cited| the spline of Koehler et al. (2017)]]: [ [[https://doi.pangaea.de/10.1594/PANGAEA.871273|Access to data]] ]\\ **CFC** = 0 \\ **O<sub>3</sub>** = Preindustrial (e.g. 10 DU)  | 
| Ice sheet | Transient: Combined ice-sheet reconstruction (IcIES-NH, GSM-G and GSM-A) [ [[:data:ice_glac_1d|Access to data]] ]\\ (Abe-Ouchi et al 2013; Briggs et al 2014; Tarasov et al 2012) \\ How often to update the ice sheet is optional |
| Orography and coastlines  | Transient. To be consistent with the choice of ice sheet. \\ Orography is updated on the same timestep as the ice sheet. It is optional how often the land-sea mask is updated, but ensure consistency with the ice sheet reconstruction is maintained | 
| Bathymetry  | Keep consistent with the coastlines, and otherwise use either: \\ - Data associated with the ice sheet; it is optional how often the bathymetry is updated \\ - Preindustrial bathymetry | 
| River routing | Ensure that rivers reach the coastline \\ It is recommended (optional) to use one of the following: \\ - Self-consistent paleo-routing described in section 6.2.3 \\ - Preindustrial configuration for the model \\ - Manual/model calculation of river network to match topography  |
| Freshwater fluxes | Recommended North Atlantic option is //fSL// and a constant 0.0135 Sv flux around the Antarctic coast between 140-130 ka \\ [ {{ :exp_design:t2-fwfflux_v190201.txt |Access to data}} ] (''md5sum t2-fwfflux_v190201.txt'' => ''5d073eb89df1c884fc654de930840d1b'')\\ - //fSL// : meltwater flux based on changes in sea-level \\ - //fIRD// : meltwater flux based on Norwegian Sea and North Atlantic IRD \\ - //fIC// : meltwater flux based on ice-sheet changes \\ - //fSL2// : meltwater flux based on changes in sea-level and triangular input max. 0.15 Sv between 131-128 ka on the Antarctic coast \\ - //fUN// : Globally uniform meltwater input based on sea-level changes  |
| Vegetation & land cover \\ Aerosols (dust) | Prescribed preindustrial cover or dynamic vegetation model \\ Prescribed preindustrial distribution or prognostic aerosols |

==== Focused simulations ====

  * Empty
  * Empty

==== Paleorecords to use for model-data comparisons ====

=== Overview ===

See Table 3 and Table 4 of the [[https://doi.org/10.5194/gmd-12-3649-2019|Penultimate Deglaciation GMD paper]]

^  Table 3  ^  Table 4  ^
|  Click on a table to get a bigger version,\\ or download the GMD paper  ||
|{{ :exp_design:t2_gmd_table3_v190201.png?direct }}|{{ :exp_design:t2_gmd_table4_v190201.png?direct }}|

=== Data ===

You will find below the data mentioned in Table 3, Table 4, Figure 8 and Figure 9 of the GMD paper

The data files have a version string (''_vYYmmDD'') in their file name, indicating when they have been uploaded to this site (in case we have to update them later and use a more recent version/date).

You can also check that you have the correct version of the files by computing their checksums (''md5sum data_file'') and comparing them to the checksums in the table below. Getting a different checksum means that you either have a wrong version of the file, or that the file content was corrupted during the transfer

^  Data  ^  version\\ string  ^  md5sum  ^ 
| {{ :exp_design:ch69k09_revisedage_v190201.txt |CH69-K09}} (txt) | _v190201 | 4f4edfba575324b504beb20ade0b9d28 |
| {{ :exp_design:md952042_revisedage_v190201.txt |MD95-2042}} (txt) | _v190201 | cc24515a1a59417486e80155c4ebbbaa |
| {{ :exp_design:odp976_revisedage_v190201.txt |ODP976}} (txt) | _v190201 | 6958069100a8df8fde00dd06e0f9bd52 |
| {{ :exp_design:odp980_revisedage_v190201.txt |ODP980}} (txt) | _v190201 | c8310b4db60415e055c131d57b6cfd56 |
| {{ :exp_design:odp983_revisedage_v190201.txt |ODP983}} (txt) | _v190201 | e7cb293ceb7b7f7a8771206ec794c938 |
| {{ :exp_design:odp1063_revisedage_v190201.txt |ODP1063}} (txt) | _v190201 | bb075a7f8fe8ffb9bd3778d6584c3924 |
| {{ :exp_design:su9003_revisedage_v190201.txt |SU90-03}} (txt) | _v190201 | 445ea11f144843ceb7f8128df5fafaf6 |
| {{ :exp_design:sl_lig_dutton2017_v190201.txt |SL_LIG_Dutton2017}} (txt) | _v190201 | c1151b63ae7c720e7b5b6b3ff2f2451a |
| {{ :exp_design:d13cstack_v190201.txt |d13Cstack}} (txt) Stack of U1308, CH69-K09 and ODP1063 | _v190201 | d44b91b35fbf6e2e142dd749200b68e4 |
| {{ :exp_design:ird-stack_v190201.txt |IRD-stack}} (txt) | _v190201 | 51bf8dd9d019bf76e3a983eddf35782e |
| {{ :exp_design:figure9_data_v190213.xlsx |Figure 9 data}} (xlsx) | _v190213 | 9ec7aae777fdce6e1447a93054622f2c |

===== References cited =====

  * Ayako Abe-Ouchi, F. Saito, K. Kawamura, M. Raymo, J. Okuno, K. Takahashi, and H. Blatter: **Insolation-driven 100,000-year glacial cycles and hysteresis of ice-sheet volume**, Nature, 500, 190–193, 2013, [[https://doi.org/10.1038/nature12374|doi:10.1038/nature12374]]
  * Berger, A.: **Long-Term Variations of Daily Insolation and Quaternary Climatic Changes**, J. Atmospheric Sci., 35(12), 2362–2367, [[http://journals.ametsoc.org/doi/abs/10.1175/1520-0469(1978)035%3C2362:LTVODI%3E2.0.CO%3B2|doi:10.1175/1520-0469(1978)035<2362:LTVODI>2.0.CO;2]], 1978.
  * Robert D. Briggs , David Pollard , Lev Tarasov, **A data-constrained large ensemble analysis of Antarctic evolution since the Eemian**, Quaternary Science Reviews, Volume 103, 1 November 2014, Pages 91–115, [[http://www.sciencedirect.com/science/article/pii/S0277379114003448|doi:10.1016/j.quascirev.2014.09.003]]
  * Kageyama, M., Braconnot, P., Harrison, S. P., Haywood, A. M., Jungclaus, J., Otto-Bliesner, B. L., Peterschmitt, J.-Y., Abe-Ouchi, A., Albani, S., Bartlein, P. J., Brierley, C., Crucifix, M., Dolan, A., Fernandez-Donado, L., Fischer, H., Hopcroft, P. O., Ivanovic, R. F., Lambert, F., Lunt, D. J., Mahowald, N. M., Peltier, W. R., Phipps, S. J., Roche, D. M., Schmidt, G. A., Tarasov, L., Valdes, P. J., Zhang, Q. and Zhou, T.: **PMIP4-CMIP6: the contribution of the Paleoclimate Modelling Intercomparison Project to CMIP6**, Geosci. Model Dev. Discuss., 1–46, [[http://www.geosci-model-dev-discuss.net/gmd-2016-106/|doi:10.5194/gmd-2016-106]], 2016.
  * P. Koehler and C. Nehrbass-Ahles and J. Schmitt and T.F. Stocker and H. Fischer: **A 156 kyr smoothed history of the atmospheric greenhouse gases CO<sub>2</sub>, CH<sub>4</sub>, and N<sub>2</sub>O and their radiative forcing**, Earth System Science Data, 9, 363–387, [[https://www.earth-syst-sci-data.net/9/363/2017/|doi:10.5194/essd-9-363-2017]], 2017.
  * Lev Tarasov, Arthur S. Dyke, Radford M. Neal and W.R. Peltier, **A data-calibrated distribution of deglacial chronologies for the North American ice complex from glaciological modeling**, Earth and Planetary Science Letters, Volumes 315–316, 15 January 2012, Pages 30–40, [[http://www.sciencedirect.com/science/article/pii/S0012821X11005243|doi:10.1016/j.epsl.2011.09.010]]
  * Veres, D., Bazin, L., Landais, A., Toyé Mahamadou Kele, H., Lemieux-Dudon, B., Parrenin, F., Martinerie, P., Blayo, E., Blunier, T., Capron, E., Chappellaz, J., Rasmussen, S. O., Severi, M., Svensson, A., Vinther, B. and Wolff, E. W.: **The Antarctic ice core chronology (AICC2012): an optimized multi-parameter and multi-site dating approach for the last 120 thousand years**, Clim Past, 9(4), 1733–1748, [[http://www.clim-past.net/9/1733/2013/|doi:10.5194/cp-9-1733-2013]], 2013.