Sea ice drift daily gridded data derived from satellite observations

This dataset provides daily gridded fields of sea ice drift vectors for both hemispheres derived from satellite passive microwave brightness temperatures and atmospheric reanalysis data. Sea ice is an important component of our climate system and a sensitive indicator of climate change. Its presence or retreat significantly affects ocean-atmosphere interactions, the Earth’s energy budget as well as marine ecosystems. It is classified as an Essential Climate Variable by the Global Climate Observing System.

Sea ice drift refers to the movement of ice, represented by vectors showing how far and in which direction the ice travels over a set time period (here 24 hours). It is one of the parameters commonly used to characterise sea ice. This dataset is of relatively coarse resolution and based on data from several satellite sensors:

• the Special Sensor Microwave/Imager (SSM/I; 1991–2006)
• the Special Sensor Microwave Imager/Sounder (SSMIS; 2005 onward)
• the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) sensor (2002–2011) and its successor, AMSR2 (2012–2017)

Wind data from the ERA5 atmospheric reanalysis is also used during the summer melt season. The underlying algorithm uses satellite data from the near-90GHz channel on SSM/I and SSMIS, and from the 37GHz channel on AMSR-E and AMSR2. The satellite images are processed to enhance key features, making it easier to track the movement of sea ice. Data from different satellites are combined to create a single product. During summer and when satellite data is unavailable, missing data is filled using a free-drift model based on ERA5 wind data and trained on AMSR-E and AMSR2 drift data. The product is gap-filled with spatial interpolation where needed.

This dataset is brokered on behalf of the Copernicus Climate Change Service by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) Ocean and Sea Ice Satellite Application Facility (OSI SAF).