PMIP4 GLAC-1D ice-sheet data

Grid

nb_lat, nb_lon = 360, 360

latitude_values = [ -89.75, -89.25, -88.75, … 88.75, 89.25, 89.75 ]

longitude_values = [ 0.5, 1.5, 2.5, … 357.5, 358.5, 359.5 ]

time axis: see the Time steps section below

Time steps and data files

26 ka BP to 0

261 time steps in one file : data every 100 years, from 26k to 0k BP

time_values = [ -26. , -25.9, -25.8, … -0.2, -0.1, 0. ]

all the variables and all the time steps are in the same file: TOPicemsk.GLACD26kN9894GE90227A6005GGrBgic.nc

140 ka to 122 ka BP

37 time steps in one file : data every 500 years, from 140k to 122k BP

time_values = [ -140, -139.5, -139, … -123, -122.5, -122 ]

all the variables and all the time steps are in the same file: TopoIcem-140-122k.nc

Variables

HDC: GLAC contemp. elevation(masl), meters

on continents (including ice sheets) and ice shelves: surface altitude (including ice sheets/shelves)

on ice-free ocean: bathymetry

HDCB: GLAC contemp. elevation(masl), bathymetry for floating ice, meters

on continents (including ice sheets) and ice shelves: surface altitude (including ice sheets)

on ice-shelves: altitude of the bottom of the floating ice

on ice-free ocean: bathymetry

ICEM: GLAC ice mask, fraction

ice fraction values between 0.0 (no ice) and 1.0 (100% ice)

Notes:

The land-sea mask can be computed with:

HDCB > 0 : ls_mask = 1 (land)

HDCB ≤ 0 : ls_mask = 0 (no land)

Computing the HDC-HDCB difference yields:

ice-shelves thickness where there are ice shelves

0.0 everywhere else

Freshwater fluxes

Melt-uniform option

Check the Download section to access the GLAC-1D_fwf_uniform.txt data file

Melt-routed option

References

Please cite all the following papers:

Lev Tarasov and W. Richard Peltier Greenland glacial history and local geodynamic consequences, Geophysical Journal International, 150, July 2002, Pages 198-229, doi:10.1046/j.1365-246X.2002.01702.x

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, doi:10.1016/j.epsl.2011.09.010

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, doi:10.1016/j.quascirev.2014.09.003

Lev Tarasov, Anna Hughes, Richard Gyllencreutz, Oystein Strand Lohne, Jan Mangerud and John-Inge Svendsen, The global GLAC-1c deglaciation chronology, melwater pulse 1-a, and a question of missing ice, IGS Symposium on Contribution of Glaciers and Ice Sheets to Sea-Level Change, 2014

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, doi:10.1038/nature12374

Download

You will find below a table with all the available data files, and their md5sum checksum (if you want to check that you download was OK, you can just type md5sum file.nc and compare the result to what is displayed in the table).

If you want to download a file, click on the ice_sheet download link and then on the file you need.

md5sum output	Data file
58b651c86c4f49ee6375ba1ab818e2be	GLAC-1D_fwf_uniform.txt
e8be8847a4dabd0a446682d51f6d77c3	TOPicemsk.GLACD26kN9894GE90227A6005GGrBgic.nc
74bf007ae6d7deb53cccb13feeea4ab6	GLAC1DHiceF26.nc
d886af74f68ee59751b2cd49679cb013	GLAC1DdrainagePointerF26ka.nc
f0afcb1b73c7ae30c33826e57f93c6ba	TopoIcem-140-122k.nc