Global Sea Ice Type

Operational Near real time product

Ice classes are assigned from atmospherically corrected SSMIS brightness temperatures and ASCAT backscatter values, using a Bayesian approach. Both the sea ice edge product and the sea ice type product are classification products differing between different ice classes. Sea ice type differs between First-year ice and Multiyear ice which are defined from target regions of known ice types. The product series is operational since 2005 (version OSI-403-b since 15/09/2015, version OSI-403-c since 30/05/2017).

Acronym : GBL SITY
Product navigator reference :


OSI SAF producer : Norwegian Meteorological Institute
Identifier : OSI-403-d
Digital object identifier (DOI) 10.15770/EUM_SAF_OSI_NRT_2006
Acronym for EDC (APNM) : OSITYGBN
Processing level : L3
Satellite input : DMSP/SSMIS, Metop/ASCAT and GCOM-W/AMSR-2
Other input : ECMWF forecast for atmospheric correction
Frequency : 1 per day
Central time : 12:00
Timeliness : 5 h
Spatial coverage : global
Spatial sampling : 10 km
File Formats : HL FTP Server (NetCDF4), EDC (NetCDF4), EUMETCast (NetCDF4)
Characteristics & methods : Discrimination First year, Multi year.
Multisensor analysis, daily average. Risk mitigation against sensor degradation.
Data Access
Main Diffusion Means : HL FTP server, last 31 days (hosted by MET Norway) :
Archive HL FTP server :
Other means :



Accuracy Requirements
Target accuracy : 100000 km2 monthly in difference from running mean
Verification/validation method : Compare multi-year area with 11-days running mean.
Applications and users
Usage : NWP and Ocean/Ice models, operational Met and Sea Ice services.
Authorised to be operational / released :
Declared operational / released since :
On EUMETCast since :
On EDC since :
On FTP server since :
Expected date for operational/released :
First date :
Last date :
  • ​Introducing for the first time Sea Ice Type for the Southern Hemisphere

  • Using Metop-B and -C, instead of Metop-A and -B (in OSI-402-c)

  • ​Switching from NetCDF3 to NetCDF4 as product format

  • ​Introducing associated uncertainty fields. The uncertainty field replaces the previous ‘confidence level” variable which will disappear. The confidence level can be reconstructed from the new uncertainty variable.

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