This page was moved to the PMIP4 web site on May 4th 2016!\\ Please use the new web page to get up-to-date information!!\\ https://pmip4.lsce.ipsl.fr/doku.php/data:ice ====== PMIP4-CMIP6 ice-sheet data ====== You will find on this page the boundary condition data that you have to use for the **LGM** and the **Last Deglaciation** experiments Please make sure to read the [[#how_to_use_the_data|HOWTO]] section in order to use the data correctly! Get in touch with the following people if you have questions: | [[Masa.Kageyama@lsce.ipsl.fr|Masa Kageyama]] | LGM | | [[R.Ivanovic@leeds.ac.uk|Ruza Ivanovic]] | Last Deglaciation | | [[Didier.Roche@lsce.ipsl.fr|Didier Roche]] | LGM, Last Deglaciation | | [[Jean-Yves.Peterschmitt@lsce.ipsl.fr|Jean-Yves Peterschmitt]] | Technical questions | ===== How to use the data ===== * Choose the type of boundary condition you want to use. Look at the available data below, and at the [[pmip3:cmip6:design:21k:gallery|ice-sheet gallery]] page. * Do not forget to document what you have chosen! * blahblah * After processing the boundary condition data, send a copy the BC data //as seen by your model// to [[Jean-Yves.Peterschmitt@lsce.ipsl.fr|Jean-Yves Peterschmitt]]: netCDF file and plot ===== Ice-sheet data ===== The input data for the boundary conditions is available in **netCDF files** provided by Dick Peltier and Lev Tarasov. You will find below some technical details about the data, and the related publications to cite ==== Data history ==== The data files may change a bit (rename or standardize the data, etc...) and you will find the change list below ==== Peltier ICE-6G-C for PMIP4 ==== === Grid === * nb_lat, nb_lon = 1080, 2160 (regular 10 minutes intervals) * latitude_values = [ -89.91667175, -89.75, -89.58334351, ... 89.58333588, 89.75 , 89.91666412 ] * longitude_values = [ 0., 0.16666667, 0.33333334, ... 359.5, 359.66668701, 359.83334351 ] * NO time axis (1 time step per file) === Time steps and data files === * 48 time steps in 48 files, from 0k to 26k BP : data every 500 years from 0k to 21k BP, then every 1000 years till 26k BP * file names = ''I6_C.VM5a_10min..nc''\\ with in [0, 0.5, 1, ..., 20, 20.5, 21, 22, 23, 24, 25, 26] * all the variables for the same time step are in the same file === Variables === * **Topo**: Topography (Point-value altitude), meters * on continents: surface altitude (including grounded ice sheet) * on ice-free oceans, and where there is floating ice (ice shelves): bathymetry * **Orog**: Orography (Point-value surface altitude), meters * on continents: altitude (including grounded ice sheet) * on ice-free oceans: 0.0 (zero) * on ice-shelves: surface altitude * **sftlf**: Point-value Landmask, % * values are ''0'' (not land) or ''100'' (land) * does not include floating ice * **sftgif**: Point-value Icemask, % * values are ''0'' (not ice) or ''100'' (ice) * floating ice is included Notes: * Computing the ''sftlf-sftgif'' difference yields: * 100: where there is land without ice * -100: where there is floating ice-sheet * 0: elsewhere === References === Please cite **all** following papers: * Describe the new Antarctic component of the model: Argus, D.F., Peltier, W.R., Drummond, R. and Moore, A.W. - **The Antarctica component of postglacial rebound model ICE-6G_C (VM5a) based upon GPS positioning, exposure age dating of ice thicknesses, and relative sea level histories**. Geophys. J. Int., 198, 537-563, 2014, [[http://gji.oxfordjournals.org/content/early/2014/05/29/gji.ggu140|10.1093/gji/ggu140]] * Describe the complete model: Peltier, W.R., Argus, D.F. and Drummond, R. (2015) **Space geodesy constrains ice-age terminal deglaciation: The global ICE-6G_C (VM5a) model**. J. Geophys. Res. Solid Earth, 120, 450-487, [[http://onlinelibrary.wiley.com/doi/10.1002/2014JB011176/abstract|doi:10.1002/2014JB011176]] === Download === FIXME ==== Tarasov GLAC-1D for PMIP4 ==== === 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 === * 261 time steps in one file, from 0k to 26k : data every 100 years, from 0k to 26k 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'' === 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 === References === Please cite **all** the following papers: * L. Tarasov and W. Richard Peltier **Greenland glacial history and local geodynamic consequences**, Geophysical Journal International, 150, 198-229, [[http://onlinelibrary.wiley.com/doi/10.1046/j.1365-246X.2002.01702.x/abstract|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, [[http://www.sciencedirect.com/science/article/pii/S0012821X11005243|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, [[http://www.sciencedirect.com/science/article/pii/S0277379114003448|doi:10.1016/j.quascirev.2014.09.003]] * 4th paper to be added here (Eurasian component) === Download === FIXME \\ \\ \\ ---- [ [[pmip3:|PMIP3 Wiki Home]] ] - [ [[pmip3:wiki_help|Help!]] ] - [ [[wiki:syntax|Wiki syntax]] ]