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Full catalog/SMERGE_RZSM0_40CM
SMERGE_RZSM0_40CM·v2.0·dataset

How wet the soil is down to 40 cm (daily)

Smerge-Noah-CCI root zone soil moisture 0-40 cm L4 daily 0.125 x 0.125 degree V2.0 (SMERGE_RZSM0_40CM) at GES DISC
land NASA GES_DISC Level 4
In plain English

What it measures. How much moisture is in the soil down to 40 cm deep (the root zone), plus moisture anomalies and a quality flag, across the continental United States.

How it's made. Made by merging a U.S. land-surface model with satellite soil-moisture retrievals from the European Space Agency, delivered as a daily grid spanning 1979 to 2019.

How & where you'd use it. Useful for drought monitoring, agriculture, and water-cycle studies, offering a long, consistent record of soil wetness across the U.S.

What's measured

AGRICULTURE › SOILS › SOIL MOISTURE/WATER CONTENTLAND SURFACE › SOILS › SOIL MOISTURE/WATER CONTENT › ROOT ZONE SOIL MOISTURE

Coverage & cadence

  • Time span1979-01-02 → 2019-05-10
  • Measured bySMERGE (NOT APPLICABLE)
  • Processing levelLevel 4
  • Spatial extent-125, 25, -67, 53
  • StatusCOMPLETE

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

Smerge-Noah-CCI root zone soil moisture 0-40 cm L4 daily 0.125 x 0.125 degree V2.0 is a multi-decadal root-zone soil moisture product. Smerge is developed by merging the North American Land Data Assimilation System (NLDAS) land surface model output with surface satellite retrievals from the European Space Agency Climate Change Initiative. The data have a 0.125 degree resolution at a daily time-step, covering the entire continental United States and spanning nearly four decades (January 1979 to May 2019). This data product contains root-zone soil moisture of 0 - 40 cm layer, Climate Change Initiative (CCI) derived soil moisture anomalies of 0-40 cm layer, and a soil moisture data estimation flag. This data product is the recommended replacement for the AMSR-E/Aqua root zone soil moisture L3 1 day 25 km x 25 km descending and 2-Layer Palmer Water Balance Model V001 product (LPRM_AMSRE_D_RZSM3), which will be removed from archive on June 27, 2022. Smerge provides a better root zone soil moisture estimation because it has higher data quality and longer temporal coverage.

Get the data

smerge_rzsm0_40cm_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="SMERGE_RZSM0_40CM",
    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 GES_DISC
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.