This dataset provides annual ice velocity maps of the Greenland and Antarctic Ice Sheets derived from Sentinel-1 data. The product represents the current state-of-the-art in Europe for satellite-based ice velocity data records. It follows from the European Space Agency (ESA) Climate Change Initiative (CCI) and is guided by the Global Climate Observing System (GCOS) targets for the Ice Sheets Essential Climate Variable (ECV).
Mapping ice flow velocity and its temporal changes provides key information for investigating the dynamic response of glaciers and ice sheets to changing environmental conditions and the contribution to global sea level rise. Remote sensing techniques that utilise satellite data are the only feasible manner to derive accurate surface velocities of the Greenland and Antarctic Ice Sheets on a regular basis.
The ice velocity is derived by applying feature tracking techniques using repeat-pass Sentinel-1 Synthetic Aperture Radar (SAR) data acquired in Interferometric Wide (IW) swath mode. Ice velocity is provided at 250m (Greenland) or 200m (Antarctica) grid spacing in Polar Stereographic Projection. The horizontal velocity components are provided in meters per day, towards easting and northing direction of the grid. The vertical displacement is derived from a digital elevation model (DEM). Provided is a NetCDF file with gridded maps representing the horizontal and vertical velocity components, along with maps showing the magnitude of velocity, valid pixel count and uncertainty (standard deviation). The product combines multiple ice velocity maps, derived from 6- and 12-day repeat SAR data acquired over a full year, in an annually averaged mosaic running from October 1st to September 30th (Greenland) or April 1st to March 31st (Antarctica), roughly mimicking a glaciological year. The datasets are extended on an annual basis.
This data was produced on behalf of the Copernicus Climate Change Service by ENVEO IT GmbH.
Data description
Data type | Gridded |
|---|---|
Projection | Polar-stereographic (Greenland: EPSG-3413; Antarctica: EPSG-3031) |
Horizontal coverage | Greenland and Antarctica |
Horizontal resolution | Greenland: 250 m Antarctica: 500 m |
Vertical coverage | Surface |
Vertical resolution | Single layer |
Temporal coverage | Greenland: 2014 to present Antarctica: 2021 to present |
Temporal resolution | Annual |
File format | NetCDF |
Conventions | CF-v1.7 |
Versions | Note: To access the complete time series, please download versions v1.3, v1.4, and v1.5, which are fully compatible with each other. v1.5 (Greenland: 2021-2022, 2022-2023, 250 m, updated ice-ocean mask; Antarctica 2021-2022, 2022-2023, 200 m) v1.4 (Greenland: 2020-2021, 250 m, dynamic ice-ocean mask) v1.3 (Greenland: 2014-2015, 2015-2016, 2016-2017, 2017-2018, 2018-2019, 2019-2020, 250 m, fixed ice-ocean mask) v1.2 (Greenland: 2017-2018, 2018-2019, 500 m) |
Update frequency | Annual |
Spatial gaps | Antarctica: Coverage only in areas with repeat Sentinel-1 acquisitions (Antarctic margins), no coverage in polar gap |
Main variables
Name | Units | Description |
|---|---|---|
Land ice surface easting velocity | m day-1 | Velocity of the ice surface in the eastward direction. |
Land ice surface northing velocity | m day-1 | Velocity of the ice surface in the northward direction. |
Land ice surface velocity magnitude | m day-1 | The absolute horizontal velocity of the ice surface. |
Land ice surface vertical velocity | m day-1 | Velocity of the ice surface in the vertical direction. |
Related variables
Name | Units | Description |
|---|---|---|
Land ice surface measurement count | number of pixels | The number of valid pixels used in the velocity estimate. |
Land ice surface velocity standard deviation | m day-1 | The standard deviation of the land ice surface velocity magnitude. |