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Full catalog/NSIDC-0079
NSIDC-0079·v4·dataset

How much of the sea is ice-covered (Bootstrap method)

Bootstrap Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS V004
cryosphere NASA NSIDC_CPRD Level 3 active netCDF-4
In plain English

What it measures. Daily and monthly maps of how much of the sea is covered by ice in the polar regions, on a 25-kilometer grid, stretching back to 1978.

How it's made. Derived from a long series of microwave radiometers (SMMR on Nimbus-7 and SSM/I and SSMIS on DMSP satellites) using the Bootstrap algorithm to turn microwave signals into ice-cover percentages.

How & where you'd use it. A cornerstone record for tracking sea-ice change in the Arctic and Antarctic over more than four decades, central to climate monitoring and polar research.

What's measured

CRYOSPHERE › SEA ICE › SEA ICE CONCENTRATION

Coverage & cadence

  • Time span1978-11-01 → ongoing
  • Measured byDMSP 5D-2/F11 (SSM/I) · DMSP 5D-2/F13 (SSM/I) · DMSP 5D-2/F8 (SSM/I) · DMSP 5D-3/F17 (SSMIS) · Nimbus-7 (SMMR)
  • Processing levelLevel 3
  • Spatial extent-180, 30, 180, 90
  • FormatsnetCDF-4
  • 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 sea ice concentration data set was derived using measurements from the Scanning Multichannel Microwave Radiometer (SMMR) on the Nimbus-7 satellite and from the Special Sensor Microwave/Imager (SSM/I) sensors on the Defense Meteorological Satellite Program's (DMSP) -F8, -F11, and -F13 satellites. Measurements from the Special Sensor Microwave Imager/Sounder (SSMIS) aboard DMSP-F17 are also included. The data set has been generated using the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) Bootstrap Algorithm with daily varying tie-points. Daily (every other day prior to July 1987) and monthly data are available for both the north and south polar regions. Data are gridded on the SSM/I polar stereographic grid (25 x 25 km) and provided in two-byte integer format. Data coverage began on 01 November 1978 and is ongoing through the most current processing, with updated data processed several times annually.

Get the data

nsidc-0079_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="NSIDC-0079",
    version="4",
    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.