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Description

This dataset provides daily-averaged model-simulated sea-ice and snow concentration, thickness, pressure loading, and velocity from the SASSIE ECCO Version 1 Release 1 (V1R1) ocean and sea-ice state estimate. ECCO (Estimating the Circulation and Climate of the Ocean) is a 4D ocean circulation model combining observations with a general circulation model (GCM) to estimate the complete time-evolving state of the global ocean. In this project, it was run over the Arctic polar region in support of the Salinity and Stratification at the Sea Ice Edge (SASSIE) field experiment - a NASA experiment focused on salinity anomalies in the upper ocean generated by melting sea ice. The SASSIE ECCO simulation was produced by downscaling the global ECCO state estimate from 1/3 to 1/12 degree grid cells, where the global solution provided initial and boundary conditions and atmospheric forcing. The output fields for this dataset cover the period 2014-01-15T12:00:00 to 2021-02-07T12:00:00 and are consolidated onto a single curvilinear grid face focusing on the Arctic domain, using the 5 faces of the lat-lon-cap 1080 (llc1080) native grid from the original simulation. Ocean density and pressure are provided at 90 depth levels from 0.5 meters to 6760 meters. Daily files are available in netCDF-4.
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This dataset is one of 22 produced by SASSIE ECCO - the full list can be found in the user guide. To cite all 22 datasets with a single DOI, please cite the user guide (citation details and DOI can be found within the user guide).

Version Description

Version 1, Release 1

Product Summary

Platforms
MITgcm
Location
ARCTIC
Coordinate System
GEODETIC
Granule Spatial Representation
GEODETIC
Temporal Extent
2014-01-15 to 2021-02-08
Temporal Resolution
1 Day
Data Partner
Physical Oceanography Distributed Active Archive Center, Jet Propulsion Laboratory, NASA (NASA/JPL/PODAAC)
Concept ID
C3677617030-POCLOUD
Data State
COMPLETE
Number of Files/Granules
2581
Processing Level
4
Science Keywords
SEA ICE SPEED ,
SEA ICE DIRECTION ,
Ice Depth/Thickness ,
Snow Depth ,
Sea Ice Concentration

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

Marie Zahn, M. W. (2026). SASSIE ECCO Sea-Ice and Snow Concentration, Thickness, and Velocity - Daily Mean llc1080 Grid (Version 1 Release 1) [Data set]. NASA Physical Oceanography Distributed Active Archive Center. https://doi.org/10.5067/SEL1D-ICO11 Date Accessed: 2026-01-29

Documents

Variables

Variables are a set of physical properties whose values determine the characteristics or behavior of something. For example, temperature and pressure are variables of the atmosphere. Parameters and variables can be used interchangeably. Variable level attributes provide individual information for each variable.

The Name in this table is the variable name. Fill value indicates missing or undefined data points in a variable. Valid range is the range of values the variable can store. Scale factor is used to increase or decrease the size of an object and can be used to correct for distortion. For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
i In the Arakawa C-grid system, tracer (e.g., THETA) and &#039;v&#039; variables (e.g., VVEL) have the same x coordinate on the model grid. N/A int N/A N/A 1
i_g In the Arakawa C-grid system, &#039;u&#039; (e.g., UVEL) and &#039;g&#039; variables (e.g., XG) have the same x coordinate on the model grid. N/A int N/A N/A 1
j In the Arakawa C-grid system, tracer (e.g., THETA) and &#039;u&#039; variables (e.g., UVEL) have the same y coordinate on the model grid. N/A int N/A N/A 1
j_g In the Arakawa C-grid system, &#039;v&#039; (e.g., VVEL) and &#039;g&#039; variables (e.g., XG) have the same y coordinate. N/A int N/A N/A 1
SIarea Fraction of ocean grid cell covered with sea-ice [0 to 1]. CF Standard Name Table v73: &#039;Area fraction&#039; is the fraction of a grid cell&#039;s horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. Sea ice area fraction is area of the sea surface occupied by sea ice. It is also called &#039;sea ice concentration&#039;. &#039;Sea ice&#039; means all ice floating in the sea which has formed from freezing sea water, rather than by other processes such as calving of land ice to form icebergs. https://cfconventions.org/Data/cf-standard-names/73/build/cf-standard-name-table.html. Defined using CF Standard Name Table v73: &#039;Area fraction&#039; is the fraction of a grid cell&#039;s horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. Sea ice area fraction is area of the sea surface occupied by sea ice. It is also called &#039;sea ice concentration&#039;. &#039;Sea ice&#039; means all ice floating in the sea which has formed from freezing sea water and precipitation, rather than by other processes such as calving of land ice to form icebergs. https://cfconventions.org/Data/cf-standard-names/73/build/cf-standard-name-table.html 1 float 9.96921E+36 0 to 1 1
sIceLoad Total mass of sea-ice and snow in a model grid cell averaged over model grid cell area. Note: sIceLoad is used to correct model sea level anomaly, ETAN, to calculate dynamic sea surface height, SSH. In the model, sea-ice is treated as floating above the sea level with ETAN tracing the location of the ocean-ice interface. Consequently, sea-ice growth in the model lowers ETAN and sea-ice melting raises ETAN. Dynamic sea surface height is obtained by correcting ETAN by the weight of ice and snow directly above following Archimedes’ principle. kg m-2 float 9.96921E+36 0 to 4180.583984375 1
SIheff Sea-ice thickness averaged over the entire model grid cell, including open water where sea-ice thickness is zero. Note: sea-ice thickness over the ICE-COVERED fraction of the grid cell is SIheff/SIarea m float 9.96921E+36 0 to 4.4050874710083 1
SIhsnow Snow thickness averaged over the entire model grid cell, including open water where snow thickness is zero. Note: snow thickness over the ICE-COVERED fraction of the grid cell is SIhsnow/SIarea m float 9.96921E+36 0 to 0.81472903490067 1
SIuice Horizontal sea-ice velocity in the +x direction at the &#039;u&#039; face of the tracer cell on the native model grid. Note: in the Arakawa-C grid, horizontal velocities are staggered relative to the tracer cells with indexing such that +SIuice(i_g,j) corresponds to +x fluxes through the &#039;u&#039; face of the tracer cell at (i,j,k=0). Also, the model +x direction does not necessarily correspond to the geographical east-west direction because the x and y axes of the model&#039;s curvilinear lat-lon-cap (llc) grid have arbitrary orientations which vary within and across tiles. m s-1 float 9.96921E+36 -0.80239057540894 to 0.94555097818375 1
SIvice Horizontal sea-ice velocity in the +y direction at the &#039;v&#039; face of the tracer cell on the native model grid. Note: in the Arakawa-C grid, horizontal velocities are staggered relative to the tracer cells with indexing such that +SIvice(i,j_g) corresponds to +y fluxes through the &#039;v&#039; face of the tracer cell at (i,j,k=0). Also, the model +y direction does not necessarily correspond to the geographical north-south direction because the x and y axes of the model&#039;s curvilinear lat-lon-cap (llc) grid have arbitrary orientations which vary within and across tiles. m s-1 float 9.96921E+36 -1.3195742368698 to 0.86637443304062 1
time midpoint time of averaging period hours since 1992-01-01T12:00:00 int N/A N/A 1
time_bnds Start and end times of averaging period. N/A int N/A N/A 1
XC nonuniform grid spacing degrees_east float N/A -179.9994354248 to 179.99996948242 1
XC_bnds Bounds array follows CF conventions. XC_bnds[i,j,0] = &#039;southwest&#039; corner (j-1, i-1), XC_bnds[i,j,1] = &#039;southeast&#039; corner (j-1, i+1), XC_bnds[i,j,2] = &#039;northeast&#039; corner (j+1, i+1), XC_bnds[i,j,3] = &#039;northwest&#039; corner (j+1, i-1). Note: &#039;southwest&#039;, &#039;southeast&#039;, northwest&#039;, and &#039;northeast&#039; do not correspond to geographic orientation but are used for convenience to describe the computational grid. See MITgcm documentation for details. N/A float N/A N/A 1
XU The u point is at midpoint between the &#039;southwest&#039; and &#039;northwest&#039; corners of the tracer grid cell. Grid spacing is nonuniform. Note: &#039;west&#039; refers to the computational grid orientation and does not necessarily correspond to geographic west. See MITgcm documentation and Arakawa C grid notation for details. degrees_east float N/A -179.99995422363 to 179.99995422363 1
XV The v point is at midpoint between the &#039;southwest&#039; and &#039;southeast&#039; corners of the tracer grid cell. Grid spacing is nonuniform. Note: &#039;south&#039; refers to the computational grid orientation and does not necessarily correspond to geographic south. See MITgcm documentation and Arakawa C grid notation for details. degrees_east float N/A -179.99990844727 to 180 1
YC nonuniform grid spacing degrees_north float N/A 48.678619384766 to 89.978286743164 1
YC_bnds Bounds array follows CF conventions. YC_bnds[i,j,0] = &#039;southwest&#039; corner (j-1, i-1), YC_bnds[i,j,1] = &#039;southeast&#039; corner (j-1, i+1), YC_bnds[i,j,2] = &#039;northeast&#039; corner (j+1, i+1), YC_bnds[i,j,3] = &#039;northwest&#039; corner (j+1, i-1). Note: &#039;southwest&#039;, &#039;southeast&#039;, northwest&#039;, and &#039;northeast&#039; do not correspond to geographic orientation but are used for convenience to describe the computational grid. See MITgcm documentation for details. N/A float N/A N/A 1
YU The u point is at midpoint between the &#039;southwest&#039; and &#039;northwest&#039; corners of the tracer grid cell. Grid spacing is nonuniform. Note: &#039;west&#039; refers to the computational grid orientation and does not necessarily correspond to geographic west. See MITgcm documentation and Arakawa C grid notation for details. degrees_north float N/A 48.652774810791 to 89.984642028809 1
YV The v point is at midpoint between the &#039;southwest&#039; and &#039;southeast&#039; corners of the tracer grid cell. Grid spacing is nonuniform. Note: &#039;south&#039; refers to the computational grid orientation and does not necessarily correspond to geographic south. See MITgcm documentation and Arakawa C grid notation for details. degrees_north float N/A 48.678611755371 to 89.984642028809 1
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