Parametrized Rain Impact Model (PRIM) for SMAP L2 V1.0 Dataset Release

The PO.DAAC is pleased to announce the availability of the PI-produced Parametrized Rain Impact Model (PRIM) for SMAP Level-2 V1.0 dataset produced by the University of Central Florida (UCF) Remote Sensing Lab (CFRSL), Orlando, FL and the University of Washington (UW) Applied Physics Lab (APL), Seattle, WA. This dataset provides sea water salinity on a 0.25-degree spatial grid and covers March 31, 2015 through October 1, 2021. Additional coverage may be provided in the future depending on the availability of required inputs such as rain rate from the IMERG V6B Final Run product.

Each PRIM data file corresponds to one JPL SMAP Level 2B CAP Sea Surface Salinity V5.0 file, and contains coverage for one orbit on a given day. Its primary parameters include sea surface salinity at the surface (PRIM_S0m), at 1m depth (PRIM_S1m), and at 5m depth (PRIM_S5m), as well as ocean stratification probability (PSS). The data are distributed in netCDF4 file format and comply with CF/ACDD metadata conventions.

The PRIM dataset and user guide are accessible via the dataset landing page on PO.DAAC web portal. Users are recommended to download the data using the podaac-data-subscriber. We also encourage users to visit PO.DAAC Cloud Data Page for detailed information about how to access the data from NASA Earthdata Cloud. General information regarding the SMAP mission is available from the mission website.


Jacob et al. 2023. Parameterized Rain Impact Model near-surface salinity and stratification estimates. Ver. 1.0. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at

Drushka, K., Asher, W. E., Ward, B., & Walesby, K. (2016). Understanding the formation and evolution of rain-formed fresh lenses at the ocean surface. Journal of Geophysical Research: Oceans, 121(4), 2673-2689.

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