This dataset provides gridded sea ice thickness data for the Arctic, derived from satellite observations. Sea ice plays a vital role in the climate system, influencing air-sea interactions, the Earth’s energy balance, and marine ecosystems. It is recognised by the Global Climate Observing System as an Essential Climate Variable. Sea ice thickness is a key characteristic used alongside other parameters such as concentration, edge, and type, all available in the Climate Data Store.
Sea ice thickness is estimated from satellite radar altimetry, which measures the sea ice freeboard—the height difference between the ice surface and open water in leads (areas of open water within the sea ice). Since most sea ice floats below the surface, total thickness is roughly 10 times the freeboard. Snow cover, however, complicates this relationship, requiring additional data on snow depth and density for accurate estimates.
This dataset provides both a Level-3 Collated (L3C) product (with spatial gaps) based on altimetry measurements from Envisat and CryoSat-2, and a Level-4 (L4) product (gap-filled) based on a combination of altimetry measurements from CryoSat-2 and L-band radiometry measurements from Soil Moisture and Ocean Salinity (SMOS) mission. More details about each product are provided below. The L4 product offers improved accuracy for thin ice, higher temporal resolution, and complete spatial coverage. However, its shorter time span makes it less suitable for assessing long-term climate trends compared to L3C. Further details about each product are provided below. Both products are limited to the Arctic and the winter months (October–April), as melt conditions in other months introduce biases. There is currently no sea ice thickness data of sufficient quality available for the Southern Hemisphere. The Level-3 algorithm was developed through the ESA Climate Change Initiative on Sea Ice.
Variables
Name | Units | Description |
|---|---|---|
Sea ice thickness | m | Mean thickness of the sea ice layer in the area of the grid cell covered by ice. |
Related variables
Name | Units | Description |
|---|---|---|
Uncertainty | m | Statistical uncertainty of the sea ice thickness retrieval algorithm. It corresponds to the mean uncertainty of along-track values at full sensor resolution. |
Status flag | Dimensionless | Status flag detailing what filters, masks, or processing steps were applied to each pixel in the sea ice thickness retrievals. See Product User Guide for details. |
Quality flag | Dimensionless | Quality flag for the sea ice thickness retrievals. It provides an expert guess on data quality (nominal, intermediate, low) based on a list of criterions. See Product User Guide for details. |