Resuming Sea Ice Climate Production

Production of sea-ice products is resuming after the SSMIS data outage. This service message pertains to sea-ice climate products: the Sea Ice Concentration ICDR OSI-430-a and the Sea Ice Index, OSI-420.

As mentioned in earlier service messages (#3018, #3021, #3023), there was an outage of SSMIS data from the data provider in the US, which resulted in missing sea-ice products from September 12 to 17. We are now receiving SSMIS data since September 18 and have resumed the production of sea-ice climate data.

Production of OSI-430-a fasttrack has resumed and the products for 2024-09-18 were distributed today. Please note, that the Southern Hemisphere product contains two data gaps in the 2024-09-18 product. In general, we advise caution with the quality of the fasttrack ICDR data in the few days after the interruption and invite users to wait for the nominal ICDR files produced with a 16-day latency.

Computation of the Sea Ice Index, OSI-420, has also resumed. Because OSI-420 uses the fasttrack ICDR files, we advise caution with interpreting its values in the few days after the interruption, and invite users to wait for the sea-ice index values based on the nominal ICDR. We will monitor the evolution of the OSI-420 values in the next few days until it stabilizes.

Note that the period of missing SSMIS data unfortunately overlaps with the time when we can expect the annual minimum of the sea-ice extent in the Northern Hemisphere and the annual maximum extent in the Southern Hemisphere. Therefore, it may not be possible to come to an exact conclusion on this year’s minimum and maximum sea-ice extents based on the SSMIS data alone. 

We currently do not have SSMIS data for the period from 2024-09-12 to 2024-09-17 and do not yet know if we can reprocess these days later, or if the data is considered lost. We will inform our users if the missing data have been retrieved.