Ice-sheet model output of Antarctic Ice Sheet simulations spanning 30,000 years BP to 5000+ years in the future.
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Ice Sheet Model Output, West Antarctic Ice Sheet Deglaciation, Version 1
Geographic Coverage
Spatial Coverage: |
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Spatial Resolution: |
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Temporal Coverage: |
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Temporal Resolution: | Varies |
Parameter(s): |
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Platform(s) | Laboratory |
Sensor(s): | Comp |
Data Format(s): |
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Version: | V1 |
Data Contributor(s): | David Pollard |
Metadata XML: | View Metadata Record |
Data Citation
As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.
Pollard, D. 2015. Ice Sheet Model Output, West Antarctic Ice Sheet Deglaciation, Version 1. [Indicate subset used]. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: http://dx.doi.org/10.7265/N5NC5Z53. [Date Accessed].Literature Citation
As a condition of using these data, we request that you acknowledge the author(s) of this data set by referencing the following peer-reviewed publication.
Pollard, D. and R. M. DeConto. 2012. Description of a hybrid ice sheet-shelf model, and application to Antarctica, Geoscientific Model Development. 5. 1273-1295. http://dx.doi.org/10.5194/gmd-5-1273-2012
Detailed Data Description
This data set contains ice-sheet model output of Antarctic ice sheet simulations spanning 30,000 years BP to 5000+ years into the future, in large ensembles of up to 625 individual runs with varying parameter values. The files can be used to generate statistics of variability in the model output.
Data are in NetCDF (.nc) abd ASCII text formats. The ASCII files are tab-delimited.
Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/nsidc0639_pollard
directory. Within this directory there are six folders, and within each folder, there are between 25 to 625 files for a total of 2541 files. See Figure 1 for the folder names and Figure 2 for a sample of the file listing (this image is only a partial representation of the files in the directory).


The file names indicate the parameter value of each run. Files named fort.92_*.nc
are netCDF files, and those named fort.22_*
are ASCII tab-delimited text.
The NetCDF files range from 5.2 to 16.8 MB, and the ASCII files range from .16 to 5.4 MB.
The total data volume is 6.5 GB.
The Domain Center on the grid projection is at 82.0° S; 85.0° W.
Spatial Resolution
For the model grid, the spatial resolution of the data is every 20 km.
Projection and Grid Description
Data are plotted on a polar stereographic 20 km grid, 171x171 points, spanning West Antarctica. Domain center is 82.0° S, 85.0° W.
Data were collected from 01 January 2015 to 02 January 2015. The data span from 30,000 BP to 5000+ years into the future.
Temporal Resolution
The NetCDF files have a 1000-year temporal resolution, and the ASCII tabular files have a resolution of every two years.
The parameters for this data set are:
Ice Sheet Elevation (m)
Ice Temperature (°C)
Ice Thickness (m)
Ice Velocity (m/y)
Surface Elevation (m)
Sample Data Record
NetCDF files have selected two-dimensional model fields at 1000 year intervals, on a polar stereographic 20 km grid. See Table 1 for an explanation of the main model data fields and Figure 3 for a sample of the data.
Field | Definition |
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h | ice thickness (m) |
hs | surface elevation (m) |
hb | bed elevation (m) |
maskwater | land/ocean mask (0/1) |
tb | basal temperature (°C) |
ts | surface temperatre (°C) |
ua | mean ice x-velocity (m/yr) |
va | meain ice y-velocity (m/yr) |

Tabular output (ASCII files) contain columns of domain-average or integrated model quantities at regular two year intervals for one run. Quantites are labelled in a header row. Refer to Table 2 for the main ice sheet data fields and Figure 4 for a sample of the tabular ouput data (the image is only a partial representation of the columns in the file).
Field | Definition |
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toti | total ice volume (km3) |
tota | total ice area (km2) |
esl | equivalent global sea-level rise (m) |

Software and Tools
In order to view the data, download the free software Panoply netCDF, HDF and GRIB Data Viewer from NASA
Data Acquisition and Processing
The following sources provided the main input data for the Antarctic Ice Sheet model used for this data set. See Table 3 for the variables from each data source.
Reference | Variable |
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Fretwell, P., et al. 2013. Bedmap2: improved ice bed, surface and thickness datasets for Antarctica. The Cryosphere 7(1): 375-393. doi: 10.5194/tc-7-375-2013. | Ice Thickness and Bedrock Elevation |
Bindschadler, Robert A., et al. 2013. Ice-sheet model sensitivities to environmental forcing and their use in projecting future sea level (the SeaRISE project). Journal of Glaciology 59(214): 195-224. doi: 10.3189/2013JoG12J125. | Climatological Atmospheric Precipitation and Temperature |
Liu, Z., et al. 2009. Transient Simulation of Last Deglaciation with a New Mechanism for Bølling-Allerød Warming. Science Magazine 325(5938): 310-314. doi: 10.1126/science.1171041. | Ocean Temperatures from the Global Climate Model (GCM) simulation of last 22,000 years |
Processing Steps
All data are model ouptuts, generated on computers running the numerical ice sheet model. For a description of the ice sheet model formulation, see Pollard and DeConto, 2012.
References and Related Publications
Contacts and Acknowledgments
David Pollard
Pennsylvania State University
Earth and Environmental Systems Institute
2217 Earth-Engineering Science Building
University Park, PA 16802
This research was supported by NSF Division of Polar Programs (PLR) Grant Number 1043018.
Document Information
Document Creation Date
10 November 2015
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