How wet the soil is each day (SMAP, 36 km) — SPL3SMP

In plain English

What it measures. How wet the top layer of soil is across the globe each day, mapped on a coarse 36 km grid.

How it's made. Produced from the SMAP satellite's passive microwave radiometer, which senses the natural microwave 'glow' of the soil (which changes with wetness), then resamples those readings onto a daily global grid.

How & where you'd use it. Used for drought and flood monitoring, agriculture, and weather and climate models that need to know how moist the land is.

What's measured

SPECTRAL/ENGINEERING › MICROWAVE › BRIGHTNESS TEMPERATURELAND SURFACE › SOILS › SOIL MOISTURE/WATER CONTENT › SURFACE SOIL MOISTURE

Coverage & cadence

Time span2015-03-31 → ongoing
Measured bySMAP (SMAP L-BAND RADIOMETER)
Processing levelLevel 3
Spatial extent-180, -85.044, 180, 85.044
FormatsHDF5
StatusACTIVE

What you can do with it

Track deforestation, fire scars and land-cover change
Monitor crop and vegetation health (NDVI/EVI)
Map how built-up vs. green an area is over time

Official description

This Level-3 (L3) soil moisture product provides a composite of daily estimates of global land surface conditions retrieved by the Soil Moisture Active Passive (SMAP) passive microwave radiometer. SMAP L-band soil moisture data are resampled to a global, cylindrical 36 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0).

Get the data

spl3smp_access.py

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

results = earthaccess.search_data(
    short_name="SPL3SMP",
    version="009",
    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 NSIDC_CPRD

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