Freshwater output from the Arctic
The climate of Northwest Europe is unusually warm given its latitude. This warmth is the result of a number of oceanic processes centred in the Nordic Seas and the Arctic. Over the last fifty years Arctic warming has been three times greater than the global increase in surface temperature. The aim of the ASOF-N project has been to understand the processes controlling climate change in the highest latitudes of the North Atlantic. The ASOF-N project measured freshwater flux through the Fram Strait, a sea channel connecting the Arctic Ocean and the Nordic Seas, running between Greenland and Spitsbergen. Fram Strait is the passageway where most drifting sea ice exits the Arctic. It is also the main provider of freshwater to the Labrador Sea and North Atlantic, together with the Davis Strait. In order for seasonal freshwater fluxes to be measured high-resolution spatial data was required. However, extensive ice cover prevented access to the region during winter. This problem was overcome when a coastguard ice breaker was used to penetrate into the ice. The ship also served as a base for measuring conductivity, temperature and depth of the sea thus enabling ASOF-N to carry out the first high-resolution wintertime hydrographic observations. Results from computer models were used to fill temporal and spatial gaps in the observations and to link freshwater fluxes in the East Greenland Current (EGC) with large-scale oceanic circulation. The findings made by ASOF-N will be valuable to climate scientists, since freshwater from the Arctic is believed to influence the density of seawater at high latitudes. This in turn influences currents governing oceanic heat transport to northern regions. The information will also help experts advising governments on climate change to better understand the link between freshwater output from the Arctic and climate systems.
