Learn to Use Earth Data
About
Full catalog/SPL3FTP_E
SPL3FTP_E·v004·dataset

Whether the ground is frozen or thawed each day, from NASA's SMAP satellite (9 km detail)

SMAP Enhanced L3 Radiometer Global and Northern Hemisphere Daily 9 km EASE-Grid Freeze/Thaw State V004
cryosphere NASA NSIDC_CPRD Level 3 active HDF5
Illustration of what Whether the ground is frozen or thawed each day, from NASA's SMAP satellite (9 km detail) shows
Illustration of the concept — not real satellite data.
In plain English

What it measures. Whether the land is frozen or thawed each day, for the globe and the Northern Hemisphere, on a 9 km grid.

How it's made. Derived from how surfaces appear to the SMAP satellite's microwave radiometer, using a technique that squeezes maximum detail out of the measurements and posts them to an equal-area grid.

How & where you'd use it. Useful for tracking the freeze and thaw cycle that affects growing seasons, carbon release, and water availability across cold regions.

What's measured

CRYOSPHERE › SNOW/ICE › FREEZE/THAW › TRANSITION DIRECTION

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

  • Measure sea ice, snow cover and glaciers
  • Watch ice-sheet elevation change
  • Track freeze/thaw and permafrost
Official description

This enhanced Level-3 (L3) product provides a daily composite of global and Northern Hemisphere landscape freeze/thaw conditions retrieved by the Soil Moisture Active Passive (SMAP) radiometer from 6:00 a.m. descending and 6:00 p.m. ascending half-orbit passes. This product is derived from SMAP enhanced Level-1C brightness temperatures (SPL1CTB_E). Backus-Gilbert optimal interpolation techniques are used to extract maximum information from SMAP antenna temperatures and convert them to brightness temperatures. The data are then posted to two 9 km Earth-fixed, Equal-Area Scalable Earth Grids, Version 2.0 (EASE-Grid 2.0): a global cylindrical and a Northern Hemisphere azimuthal.

Get the data

spl3ftp_e_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="SPL3FTP_E",
    version="004",
    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.