NASA’s Physical Oceanography Distributed Active Archive Center (PO.DAAC) has released a high-resolution ocean simulation over the Arctic polar region from the Estimating the Circulation and Climate of the Ocean (ECCO) project. The model run supported the Salinity and Stratification at the Sea Ice Edge (SASSIE) field experiment.
The ocean circulation and sea-ice model outputs include standard scalar quantities (ocean temperature, salinity, density, sea ice concentration, and sea ice thickness), vector quantities (three-dimensional ocean velocities and 2D sea-ice velocities), and flux terms required to close 3D ocean heat, salt, and volume budgets, in addition to sea-ice volume budgets. The model was run over a seven-year period in support of SASSIE, a NASA experiment focused on salinity anomalies in the upper ocean generated by melting sea ice.
The simulation is produced by downscaling a global, data-constrained 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 cover the period January 15, 2014, to February 7, 2021, and are consolidated onto a single curvilinear grid face. 3D variables are provided at 90 vertical depth levels from 0.5 meters to 6760 meters.
A NASA Data in Action article, Why Sea Surface Salinity Matters for Arctic Sea Ice, highlights results from a recent study using the SASSIE ECCO data to investigate the seasonal formation of a sea ice bridge associated with freshwater plumes from the Mackenzie River.
More information about the ECCO model can be found on the NASA ECCO site, and details about the simulation run for SASSIE can be found in the User Guide. Information and resources on the SASSIE mission are available on the SASSIE project website and on Earthdata’s SASSIE project page.
Version V1R1 is the first public release of the data. The model output variables are provided in netCDF format across 22 datasets, 18 of which are daily mean quantities, three are monthly snapshots, and one provides model domain geometry. Landing pages providing data access options are discoverable via the NASA Earthdata Data Catalog.
The data are accessible via several methods:
- Direct download through the NASA Earthdata Search Portal or by using the podaac-data-subscriber command line tool.
- The data can be subsetted and downloaded using OPeNDAP.
- Two virtual datasets (VDSs) are available to stream the data; one contains all monthly snapshot variables, and the other contains all daily mean variables. (Both are currently for in-cloud use only.) For more information on VDSs, see the PO.DAAC Cookbook chapter Using Virtual Datasets. The SASSIE ECCO VDSs are offered in a new experimental icechunk format - the notebook Opening an Icechunk Store on the Cookbook provides guidance on their use. S3 paths to the VDS’s are:
- s3://podaac-ops-cumulus-public/virtual_collections/SASSIE_ECCO_V1R1/SASSIE_ECCO_L4_DAILY_V1R1_virtual_s3.icechunk/ (Daily averages)
- s3://podaac-ops-cumulus-public/virtual_collections/SASSIE_ECCO_V1R1/SASSIE_ECCO_L4_SNAPSHOT_V1R1_virtual_s3.icechunk/ (Monthly snapshots)
This work was conducted at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA through the SASSIE Ocean Salinity Field Campaign (NASA Grant 80NSSC21K0832). Computational resources supporting this work were provided by the NASA High-End Computing Program through the NASA Advanced Supercomputing Division at Ames Research Center.
DOIs to the landing pages are below. To cite all 22 with a single DOI, please cite the User Guide at doi:10.5067/SEL1D-DUG11. Citation details can be found within that guide.
Citation:
Zahn, M. J., Fournier, S., Fenty, I. G., Steele, M., Wood, M., & Gaube, P. (2026) Mackenzie River freshwater controls early sea ice formation in the eastern Beaufort Sea. Geophysical Research Letters, 53, e2025GL118871. doi:10.1029/2025GL118871
If you have questions, please contact PO.DAAC user services or visit PO.DAAC on Earthdata Forum.