Whether the ground is frozen or thawed, daily — NSIDC-0477

In plain English

What it measures. Whether the land surface is frozen or thawed each day, worldwide, going back decades.

How it's made. Derived from how warm surfaces look to passive microwave sensors flown on a series of weather satellites between 1979 and 2021, combining several instruments into one continuous daily record.

How & where you'd use it. Useful for studying the start and end of the frozen season, permafrost, growing seasons, and how a warming climate is shifting freeze and thaw timing.

What's measured

TERRESTRIAL HYDROSPHERE › SNOW/ICE › FREEZE/THAW

Coverage & cadence

Time span1979-01-01 → 2023-12-31
Measured byDMSP 5D-2/F11 (SSM/I) · DMSP 5D-2/F13 (SSM/I) · DMSP 5D-2/F8 (SSM/I) · DMSP 5D-3/F17 (SSMIS) · FY-3B (MWRI) · GCOM-W1 (AMSR2) · Nimbus-7 (SMMR)
Processing levelLevel 3
Spatial extent-179.9999, -86.7167, 179.9999, 86.7167
FormatsHDF5, GIF, GeoTIFF
StatusCOMPLETE

What you can do with it

Follow rainfall, floods and surface-water extent
Track soil moisture and the onset of drought
Monitor lakes, rivers and groundwater storage

Official description

This data set, part of the NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) program, contains a global record of the daily freeze/thaw status of the landscape. The record is derived from radiometric brightness temperatures acquired between 1979 and 2021 by four satellite-based, passive microwave sensors: the Scanning Multichannel Microwave Radiometer (SMMR), the Special Sensor Microwave/Imager (SSM/I), the Special Sensor Microwave Imager/Sounder (SSMIS), and the Advanced Microwave Scanning Radiometer 2 (AMSR2).

Get the data

nsidc-0477_access.py

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

results = earthaccess.search_data(
    short_name="NSIDC-0477",
    version="5",
    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