Operational release of the Sea-Ice Index Version 3 (OSI-420-a)

The OSI SAF sea ice team is pleased to announce the operational release of its new Sea-Ice Index Version 3.0 (OSI-420-a) on 4th May 2026. Previously distributed as a demonstrational since 2020, this version has undergone a full EUMETSAT review, including users, and will now officially be labelled as operational.

Starting from 4th May at noon, the Sea Ice Index v3.0 product files will be available at:

• FTP: ftp://osisaf.met.no/prod/ice/index/v3p0 (netCDF and text)
• THREDDS: https://thredds.met.no/thredds/osisaf/osisaf_420siiv3p0.html  (netCDF)

The previous version v2.3 will be available in parallel until 1st June 2026.

Graphics and an interactive visualisation tool will be available here:
https://osi-saf.eumetsat.int/sea-ice-index

Documentation, including the Product User Manual, Scientific Validation Report and Algorithm Theoretical Basis Document, will be available here:
https://osi-saf.eumetsat.int/products/osi-420-a

The Sea-Ice Index v3.0 computation is based on the different OSI SAF Sea-Ice Concentration v3 Climate Data Records and Interim Data Records, covering the period from October 1978 to the present, and distributed with a latency of 1 day. It provides two related but slightly different measures of Sea-Ice Extent (SIE) and Sea-Ice Area (SIA), where SIE represents the sea-ice cover with a concentration greater than 15%, and SIA is the actual surface area covered by ice weighted by concentration. The daily time series of SIE and SIA are processed to create corresponding monthly and yearly time series, along with measures of rank, minimum, and maximum values. Additionally, climatology data are provided separately for each decade and two 30-year periods, 1981-2010 and 1991-2020, including standard summary statistics such as mean, median, standard deviation, and selected percentiles.

If you have any questions, please contact the OSI SAF sea ice team on email osisaf-manager@met.no