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Description

This dataset provides daily-averaged ocean and sea-ice surface freshwater fluxes 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. Model ocean and sea-ice state estimates are dynamically and kinematically-consistent reconstructions of the three-dimensional time-evolving ocean, sea-ice, and surface atmospheric states. 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. Daily files are available in netCDF-4.

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
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
C3874470970-POCLOUD
Data State
COMPLETE
Number of Files/Granules
2581
Processing Level
4
Science Keywords
Sea Ice ,
Sea Ice ,
Precipitation ,
Evaporation ,
Precipitation ,
Runoff ,
Ice Growth/Melt

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 Ocean and Sea-Ice Surface Freshwater Fluxes - Daily Mean llc1080 Grid (Version 1 Release 1) [Data set]. NASA Physical Oceanography Distributed Active Archive Center. https://doi.org/10.5067/SEL1D-FRE11 Date Accessed: 2026-03-15

Documents

Variables

The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.

For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor Offset
EXFempmr Net surface freshwater flux from precipitation, evaporation, and runoff per unit area in open water (not covered by sea-ice). Excludes freshwater fluxes involving sea-ice and snow. Note: calculated as EXFevap-EXFpreci-EXFroff. m s-1 float 9.96921E+36 -5.6687252936172E-7 to 8.0595363272096E-8 1 N/A
EXFevap Evaporation rate per unit area of open water (not covered by sea-ice). Note: calculated using the bulk formula following Large and Yeager (2004) NCAR/TN-460+STR. m s-1 float 9.96921E+36 -1.3459994896436E-8 to 8.0596144869105E-8 1 N/A
EXFpreci Precipitation rate m s-1 float 9.96921E+36 3.8801953965176E-17 to 5.848427804267E-7 1 N/A
EXFroff River runoff freshwater flux. Note: not adjusted by the optimization. m s-1 float 9.96921E+36 0 to 1.6076070323834E-6 1 N/A
i In the Arakawa C-grid system, tracer (e.g., THETA) and 'v' variables (e.g., VVEL) have the same x coordinate on the model grid. N/A int N/A N/A 1 N/A
j In the Arakawa C-grid system, tracer (e.g., THETA) and 'u' variables (e.g., UVEL) have the same y coordinate on the model grid. N/A int N/A N/A 1 N/A
oceFWflx Net freshwater flux into the ocean including contributions from runoff, evaporation, precipitation, and mass exchange with sea-ice due to melting and freezing and snow melting. Note: oceFWflx does NOT include freshwater fluxes between the atmosphere and sea-ice and snow. The variable 'SIatmFW' accounts for freshwater fluxes out of the combined ocean+sea-ice+snow reservoir. kg m-2 s-1 float 9.96921E+36 -0.0055723050609231 to 0.0052591445855796 1 N/A
SFLUX The rate of change of total ocean salinity due to freshwater fluxes across the liquid surface and the addition or removal of mass. Note: the global area integral of SFLUX matches the time-derivative of total ocean salinity (psu s-1). Unlike oceFWflx, SFLUX includes the contribution to the total ocean salinity from changing ocean mass (e.g. from the addition or removal of freshwater in oceFWflx). g m-2 s-1 float 9.96921E+36 -0.13435481488705 to 0.13753609359264 1 N/A
SIacSubl Realized (actual) sublimation freshwater flux from sea ice; positive values remove ice mass. kg m-2 s-1 float 9.96921E+36 0 to 5.1187957978982E-6 1 N/A
SIatmFW Net freshwater flux into the combined liquid ocean, sea-ice, and snow reservoirs from the atmosphere and runoff. Note: freshwater fluxes BETWEEN the liquid ocean and sea-ice or snow reservoirs do not contribute to SIatmFW. SIatmFW counts all fluxes to/from the atmosphere that change the TOTAL freshwater stored in the combined liquid ocean, sea-ice, and snow reservoirs. kg m-2 s-1 float 9.96921E+36 -8.0579244240653E-5 to 0.0016098151681945 1 N/A
SIfwSubl Potential sublimation freshwater flux from sea ice; positive values remove ice mass. kg m-2 s-1 float 9.96921E+36 -4.7576127144566E-6 to 5.1187957978982E-6 1 N/A
SIrsSubl Residual sublimation freshwater flux term ensuring conservation of mass; positive values correspond to flux taken from the ocean. kg m-2 s-1 float 9.96921E+36 -4.7576127144566E-6 0 1 N/A
time midpoint time of averaging period hours since 1992-01-01T12:00:00 int N/A N/A 1 N/A
time_bnds Start and end times of averaging period. N/A int N/A N/A 1 N/A
WSLTMASS Surface flux correction of salinity associated with a linear free-surface configuration; applied as a mass flux term at the ocean surface. 1e-3 m s-1 float 9.96921E+36 -0.00071304809534922 to 0.00076772598549724 1 N/A
XC nonuniform grid spacing degrees_east float N/A -179.9994354248 to 179.99996948242 1 N/A
XC_bnds Bounds array follows CF conventions. XC_bnds[i,j,0] = 'southwest' corner (j-1, i-1), XC_bnds[i,j,1] = 'southeast' corner (j-1, i+1), XC_bnds[i,j,2] = 'northeast' corner (j+1, i+1), XC_bnds[i,j,3] = 'northwest' corner (j+1, i-1). Note: 'southwest', 'southeast', northwest', and 'northeast' 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 N/A
YC nonuniform grid spacing degrees_north float N/A 48.678619384766 to 89.978286743164 1 N/A
YC_bnds Bounds array follows CF conventions. YC_bnds[i,j,0] = 'southwest' corner (j-1, i-1), YC_bnds[i,j,1] = 'southeast' corner (j-1, i+1), YC_bnds[i,j,2] = 'northeast' corner (j+1, i+1), YC_bnds[i,j,3] = 'northwest' corner (j+1, i-1). Note: 'southwest', 'southeast', northwest', and 'northeast' 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 N/A
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