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Full catalog/OISSS_L4_multimission_7day_v2
OISSS_L4_multimission_7day_v2·v2.0·dataset

How salty the sea surface is, blended (7-day)

Multi-Mission Optimally Interpolated Sea Surface Salinity Global Dataset V2
ocean NASA POCLOUD Level 4 netCDF-4
In plain English

What it measures. How salty the surface of the ocean is across the globe, given as smoothed maps on a roughly 25-km grid that blend several satellites into one consistent picture.

How it's made. Built by statistically combining sea-surface salinity readings from three satellite missions (Aquarius/SAC-D, SMAP, and SMOS) and adjusting them against floating ocean sensors to keep them accurate.

How & where you'd use it. Helps researchers study ocean circulation, the water cycle, and climate, since saltiness drives how seawater moves and mixes; the blending gives a long, continuous record from 2011 onward.

What's measured

OCEANS › SALINITY/DENSITY › SALINITY › None

Coverage & cadence

  • Time span2011-08-24 → ongoing
  • Measured bySMAP (SMAP L-BAND RADIOMETER) · SAC-D (AQUARIUS_SCATTEROMETER) · SMOS (SMAP L-BAND RADIOMETER)
  • Processing levelLevel 4
  • Spatial extent-180, -90, 180, 90
  • FormatsnetCDF-4
  • StatusCOMPLETE

What you can do with it

  • Watch sea-surface temperature and marine heatwaves
  • Spot algal blooms and ocean-colour shifts
  • Support fisheries and coastal monitoring
Official description

This is a level 4 product on a 0.25-degree spatial and 4-day temporal grid. The product is derived from the level 2 swath data of three satellite missions: the Aquarius/SAC-D, Soil Moisture Active Passive (SMAP) and Soil Moisture and Ocean Salinity (SMOS) using Optimal Interpolation (OI) with a 7-day decorrelation time scale. The product offers a continuous record from August 28, 2011 to present by concatenating the measurements from Aquarius (September 2011 - June 2015) and SMAP (April 2015 present). ESAs SMOS data was used to fill the gap in SMAP data between June and July 2019, when the SMAP satellite was in a safe mode. The two-month overlap (April - June 2015) between Aquarius and SMAP was used to ensure consistency and continuity in data record. The product covers the global ocean, including the Arctic and Antarctic in the areas free of sea ice, but does not cover internal seas such as Mediterranean and Baltic Sea. In-situ salinity from Argo floats and moored buoys are used to derive a large-scale bias correction and to ensure consistency and accuracy of the OISSS dataset. This dataset is produced by the Earth and Space Research (ESR), Seattle, WA and the International Pacific Research Center (IPRC) of the University of Hawaii at Manoa in collaboration with the Remote Sensing Systems (RSS), Santa Rosa, California. More details can be found in the users guide.

Get the data

oisss_l4_multimission_7day_v2_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="OISSS_L4_multimission_7day_v2",
    version="2.0",
    bounding_box=(-122.5, 37.2, -121.8, 37.9),  # your area (W,S,E,N)
    temporal=("2024-01-01", "2024-12-31"),       # your dates
)
files = earthaccess.open(results)   # stream straight from POCLOUD
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.