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Design for the Penultimate Deglaciation experiment
You will find on this page information about the experiment design for the PMIP4 Penultimate Deglaciation experiments.
This protocol is a product of the PAGES-PMIP working group on Quaternary Interglacials (QUIGS)
Please make sure to read the 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:
| Laurie Menviel | Experimental design questions |
| Emilie Capron | Experimental design questions |
| Ruza Ivanovic | working group leader |
| Jean-Yves Peterschmitt | Technical questions or missing data |
Associated publications
- Penultimate Deglaciation experiment design, version 1:
The penultimate deglaciation: protocol for PMIP4 transient numerical simulations between 140 and 127 ka, version 1.0, Menviel et al, GMD, 2019, https://dx.doi.org/available_soon
Version 1 Specifications
For general advice on boundary condition implementation in palaeoclimate models, see 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 | PDGv1-PGMspin (PDG ⇔ Penultimate DeGlaciation - PGM ⇔ Penultimate Glacial Maximum) |
| 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-2 |
| Trace gases | CO2 = 191 ppm CH4 = 385 ppb N2O = 201 ppb CFC = 0 O3 = 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): [ Access to data ] |
| 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 | PDGv1 |
| 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 Berger (1978) [ Access to data & README ! ] |
| Solar constant | 1361.0 ± 0.51365 W m-2 |
| Trace gases | CO2 = Transient, as per the spline of Koehler et al. (2017): [ Access to data ] CH4 = Transient, as per the spline of Koehler et al. (2017): [ Access to data ] N2O = Linear increase from 201 ppb at 140 ka to 218.74 ppb at 134.5 ka then transient, as per the spline of Koehler et al. (2017): [ Access to data ] CFC = 0 O3 = Preindustrial (e.g. 10 DU) |
| Ice sheet | Transient: Combined ice-sheet reconstruction (IcIES-NH, GSM-G and GSM-A) [ Access to data ] 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 [ Access to data ] - 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
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- Empty
Paleorecords to use for model-data comparisons
Overview
See Table 3 and Table 4 of the Penultimate Deglaciation GMD paper
| Table 3 | Table 4 |
|---|---|
| Click on a table to get a bigger version, or download the GMD paper |
|
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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).
References cited
- Berger, A.: Long-Term Variations of Daily Insolation and Quaternary Climatic Changes, J. Atmospheric Sci., 35(12), 2362–2367, doi:10.1175/1520-0469(1978)035<2362:LTVODI>2.0.CO;2, 1978.
- 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, 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 CO2, CH4, and N2O and their radiative forcing, Earth System Science Data, 9, 363–387, doi:10.5194/essd-9-363-2017, 2017.
- 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, doi:10.5194/cp-9-1733-2013, 2013.