The Sea Ice Radar Altimetry (SIRAL) project of the Alfred Wegener Institute (AWI) is based on satellite radar altimetry data to investigate the sea ice mass balance and related processes to understand Arctic Change. The name of the project is also a homage to the radar altimeter onboard CryoSat-2, the Synthetic and Interferometric Radar Altimeter (SIRAL) which has been a game changer for sea-ice thickness information from satellite radar altimetry. The thickness information obtained from radar altimetry adds the third dimension to the sea ice concentration data record and is an essential parameter for climate research and numerical weather prediction.

This wiki is dedicated to the documentation of sea ice thickness data sets from radar altimeter data produced at the Alfred Wegener Institute. Please also check the blog for news and updates as well as the CS2SMOS wiki for information on merged CryoSat-2/SMOS sea ice thickness data.


Documentation: Product User Guide & Algorithm Specification: AWI CryoSat-2 Sea Ice Thickness (version 2.2)

News & Updates


(info) Minor update of CryoSat-2 REP version to v2.2.1 (see blog post)


(warning) Issue of missing CryoSat-2 NRT data (see blog post)


Reprocessed CryoSat-2 sea ice product v2.2 now available


Production of reprocessed CryoSat-2 data has been discontinued for the summer month (May - September) and will be resumed in November 2019 with an updated version (v2.2)


A new version of the CryoSat-2 data (baseline-D) has been introduced by ESA at May 28, 2019 ( Due to the change, the last day of offline reprocessed timeliness data from the previous baseline C data is April 27th, 2019. The monthly gridded product for April 2019 from reprocessed CryoSat-2 data will therefore miss data from the May 28 - May 31, 2019. A complete grid is available from near-realtime data.

A complete grid of April 2019 will be available this fall with version 2.2 of the AWI CryoSat-2 sea ice product, which will be solely based on the new CryoSat-2 baseline-D data version.

Production of near-realtime CryoSat-2 data has been discontinued for the summer month (May - September) and will be resumed in October 2019 with an updated version (v2.2)

Processing of near-realtime and reprocessed CryoSat-2 data has been resumed. (Access Data Products)

The AWI CryoSat-2 sea ice product has been updated to version 2.1 in October 2018 for the entire CryoSat-2 data period (2010 - present). The previous version 2.0 is discontinued. See Whats new in version 2.1. Full documentation in the Product User Guide.

Older blog entries can be found here.