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NOAA CoastWatch/OceanWatch/PolarWatch Sea Ice Concentration, Level 3, daily and daily 4-day rolling merge, polar stereographic mapped composites -  AMSR-2

  • The second Advanced Microwave Scanning Radiometer 2 (AMSR-2) on JAXA's Global Climate Observation Mission - Water 1 (GCOM-W1)
  • Daily composites and daily 4-day rolling merge composites
  • 10 km spatial resolution
  • Polar Stereographic projections for North Pole and South Pole 
  • Microwave not impacted by clouds
  • Source data from NOAA OSPO; NOGAPS algortihm developed by NOAA STAR (Paul Chang, Lead)




Global Change Obervation Mission - Water (GCOM-W1)

The second Advance Microwave Scanning Radiometer (AMSR-2)

Japan Aerospace Exploration Agency (JAXA)


Sea Ice Concentration (% of Sea Ice per pixel)

Sample Filename


  • GWXCW is
  • W2019203 is W year and day of year:  WYYYYdoy
  • C15 indicates number of granules in composite (generally 14 or 15)
  • Series of 6 digit numbers are start times each granule included in the composite
  • NP06 (or SP06) indicates mapped to Polar Stereographic Projection for North Pole (NP06) or South Pole (SP06) 
  • Ice Conc is product name = Ice Concentration
  • .nc is NetCDF format (CF compliant)
Processing Level

Level 3

Spatial Coverage

Polar Stereographic projection, origin at 90 degrees to 60 degree parallel (North or South)

Temporal Coverage

Daily and

Daily 4-day rolling merge


Approximately 12 to 24 hours


10 km


Polar Stereographic



Data Provider

NOAA Office of Satellite and Product Operations (OSPO) uses the GCOM-W1 AMSR-2 Algorithm Software Processor (GAASP) which takes the full orbital JAXA L1B data via NASA, applies brightness temperature bias corrections, assigns an RFI flag, performs internal reformatting, and then generates L2 products from the NOAA Operational GCOM-W1 AMSR-2 Products System Algorithm (NOGAPS).  NOAA CoastWatch obtains L2 from OSPO and generates L3 daily merged (composite) and maps to polar stereographic projection for routine distribution.


NetCDF (Climate and Forecast Convention Compliant; CF 1.4)


polar stereographic, GCOM-W1, AMSR-2, Sea Ice Concentration, JAXA

Keywords (Beta)

STAR Development (Paul Chang, Lead)

OSPO Monitoring and Documentation