How salty the sea surface is, monthly blended map — OISSS_L4_multimission_monthly_v2

In plain English

What it measures. A monthly, gap-free global map of how salty the sea surface is, expressed as sea surface salinity.

How it's made. Built by combining salinity measurements from three satellite missions (Aquarius/SAC-D, SMAP, and SMOS) and smoothing them onto a quarter-degree global grid.

How & where you'd use it. Helps scientists track the ocean's water cycle, currents, and climate patterns, since salinity reflects evaporation, rainfall, and ice melt.

What's measured

OCEANS › SALINITY/DENSITY › SALINITYOCEANS › SALINITY/DENSITY › OCEAN SALINITY › OCEAN SURFACE SALINITY

Coverage & cadence

Time span2011-08-01 → 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 monthly temporal grid. The product is the monthly mean of the level 4 OISSS dataset using 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. 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_monthly_v2_access.py

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

results = earthaccess.search_data(
    short_name="OISSS_L4_multimission_monthly_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.

What's measured

Coverage & cadence

What you can do with it

Get the data

Official links