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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.

News & Updates


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.


Sea Ice Thickness from Satellite Radar Altimetry

Further Information

CryoSat-2 has now finished its 9th winter from October to April of Arctic sea ice thickness observations. No sea-ice thickness production is now paused for the month of May through September since the snow is warming and will soon start to melt. The impact of snow melt on the sea-ice thickness retrieval is poorly understood and the production will resume in October 2019 with the next version of CryoSat-2 data.  In resume,…
The latest results from CryoSat show that the latest extrema in winter sea ice maximum extent are not necessarily accompanied by a lower mean sea ice thickness of the remaining ice. One factor certainly is that sea ice thickness is a product of thermodynamic ice growth and the acummulated dynamic forces throughout the winter. As a first step in the investigation to what extent dynamic forces have played a role in the last winter,…
With monthly mean thickness in April 2018, the 8th Arctic winter season of 2017/2018 is now complete. csawi_v2p0_sit_cryosat2.png All monthly mean CryoSat-2 Arctic sea ice thickness fields csawi_v2p0_sit_anomaly_cryosat2.png All monthly mean CryoSat-2 Arctic sea ice thickness anomaly fields
Arctic sea ice thickness information has been updated with NRT data for April 2018 and reprocessed data for March 2018. Daily, weekly and monthly products are available here: Reprocessed, Near-real time cryosat2-centralarctic-sit-201804.png cryosat2-centralarctic-sit-201804-201803.…
The production of the sea ice thickness climate data record of the ESA Climate Change Initiative (CCI) has been finalized. The files are currently being registered with their respective doi's and official dissimination will commence shortly.…

Older blog entries can be found here.

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