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Description

This is the PI-produced SMAP sea water salinity, level 2 v1.0 orbital/swath product from the NASA Soil Moisture Active Passive (SMAP) observatory. It is based on the Parameterized Rain Impact Model (PRIM) developed at the University of Central Florida (UCF) Central Florida Remote Sensing Lab (CFRSL), Orlando, FL; University of Washington (UW) Applied Physics Lab (APL), Seattle, WA. <br><br>
The PRIM product range extended from March 31, 2015 to September 30, 2021. It includes data for a range of parameters: derived SMAP sea water salinity at surface, 1m depth and 5m depth, and probability of salinity stratification (PSS), rainfall rate and wind speed data. Each data file covers one 98-minute orbit (15 files per day), and corresponds to a <a href="https://doi.org/10.5067/SMP50-2TOCS">JPL SMAP Level 2B CAP Sea Surface Salinity V5.0</a> file which corresponds to a single orbit on a given day. <br><br>
The SMAP satellite is in a near-polar orbit at an inclination of 98 degrees and an altitude of 685 km. It has an ascending node time of 6 pm and is sun-synchronous. With its 1000km swath, SMAP achieves global coverage in approximately 3 days, but has an exact orbit repeat cycle of 8 days. On board Instruments include a highly sensitive L-band radiometer operating at 1.41GHz and an L-band 1.26GHz radar sensor providing complementary active and passive sensing capabilities. Observations are global in extent and provided at 25km swath grid with an approximate spatial resolution of 60 km.

Product Summary

Platforms
SMAP
Instruments
SMAP L-BAND RADIOMETER
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Geographic Region
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
2015-03-31 to 2021-10-01
Data Partner
Physical Oceanography Distributed Active Archive Center, Jet Propulsion Laboratory, NASA (NASA/JPL/PODAAC) ,
College of Forest Resources, University of Washington (UWA/CFR)
Concept ID
C2637180124-POCLOUD
Data State
ACTIVE
Number of Files/Granules
30660
Processing Level
2
Published
Updated
Science Keywords
Salinity ,
Wind Speed ,
RAIN

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

University Of Central Florida (UCF) Central Florida Remote Sensing Lab (CFRSL). (2023). Parametrized Rain Impact Model for SMAP L2 V1.0 [Data set]. NASA Physical Oceanography Distributed Active Archive Center. https://doi.org/10.5067/PRIMS-2RSW1 Date Accessed: 2025-12-14

Documents

PI DOCUMENTATION

ALGORITHM THEORETICAL BASIS DOCUMENT (ATBD)

DATA CITATION GUIDELINES

GENERAL DOCUMENTATION

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
Kz Vertical Diffusivity Coefficient m2 s-1 double -999 0 to 1 1
lat latitude degree_north double -999 -90 to 90 1
lon longitude degree_east double -999 -180 to 180 1
PRIM_S0 Sea surface salinity estimated using PRIM 1e-3 double -999 0 to 45 1
PRIM_S1m Salinity at 1 meter depth estimated using RIM 1e-3 double -999 0 to 45 1
PRIM_S5m Salinity at 5 meters depth estimated using RIM 1e-3 double -999 0 to 45 1
PSS Probability of Salinity Stratification 1 double -999 0 to 1 1
rain_rate IMERG rain rate closest in time to SMAP observation time &amp; collocated to the center of each SMAP pixel mm hr-1 double -999 0 to 200 1
S_ref Scripps RG Argo Salinity at 5m depth 1e-3 double -999 0 to 45 1
time time of SMAP observation days since 2015-1-1 00:00:00 UTC double N/A 2458.9907407408 to 2459.0453703704 1
wind_speed wind speed from SMAP radiometer m s-1 double -999 0 to 100 1
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