Arctic climate system

CPOM uses satellite observations alongside models of ice sheet-ocean coupling, sea ice evolution and ocean dynamics to assess changes in the Arctic climate system. This includes sea ice volume and transport, ocean dynamic topography, and Greenland ice sheet mass balance.

Models of sea ice area currently give a wide range of volume estimates. To address this, we are combining data from different sources to produce a continuous record of Arctic-wide sea ice thickness since 1992. This will allow us to explore trends in thickness and volume and, combined with estimates of ice drift, mass flux out of the Arctic Ocean via the Fram Strait – the passage between Greenland and Svalbard.

Maps of November Arctic sea ice thickness recorded by CryoSat-2. Although ice is thicker than usual north of Canada, there is less ice overall in southerly regions such as the Beaufort, East Siberian and Kara Seas.

Similarly, the relationship between the Arctic Ocean and the Greenland ice sheet is not well understood. Ice losses from Greenland are among the largest sources of fresh water to the ocean, but changes to the temperature of the Arctic Ocean can also affect the ice sheet.

CPOM is producing estimates of Greenland ice sheet mass balance, as well as ice sheet runoff from regional climate models. Together, these will provide an assessment of Greenland’s freshwater contribution to the Arctic Ocean and help studies of coastal-ocean circulation. We will also continue to model the impact of the Arctic Ocean on the ice sheet.

Contains modified Copernicus Sentinel data (2015)/ENVEO/ESA CCI/FFG Description This map of Greenland ice sheet velocity was created using data from Sentinel-1A in January–March 2015 and complemented by the routine 12-day repeat acquisitions of the margins since June 2015. About 1200 radar scenes from the satellite’s wide-swath mode were used to produce the map, which clearly shows dynamic glacier outlets around the Greenland coast. In particular, the Zachariae Isstrom glacier in the northeast is changing rapidly, and recently reported as having become unmoored from a stabilising sill and now crumbling into the North Atlantic Ocean. (Colour scale in metres per day).

Greenland ice sheet velocity from Sentinel-1 data Jan-Mar 2015 Credit:Copernicus Sentinel data (2015)/ENVEO/ESA CCI/FFG