Fate of Arctic freshwater exported through Fram Strait
Around 1900 km3/yr liquid freshwater plus 2300 km3/yr of sea ice is thought to be transported southwards through Fram Strait (Serreze et al., 2006) in The East Greenland Current (EGC), but the fate of this freshwater further downstream is not well known. Freshwater exported through Fram Strait has the potential to reduce the surface density in regions of deep waters formation in the Nordic Seas and Northern North Atlantic, with consequences for the rate of the Atlantic Meridional Overturning Circulation.
Our research aims to determine the extent to which liquid and solid freshwater is lost from the EGC as it passes through the Nordic Seas. Our basic approach is to use hydrographic measurements along the EGC to monitor changes in the concentration of freshwater downstream from Fram Strait. Some of this hydrographic data is being continuously collected by CTD-SRDLs deployed from marine mammals as part of the MEOP project. The figure below shows preliminary estimates of the depth-integrated freshwater thickness based on data collected by CTD-SRDLs attached to three hooded seals between July 2007 and January 2008.
In addition to data collected by marine mammals, sections of hydrographic, ADCP and oxygen isotope ratio (d18O) measurements will be collected from a research vessel. Sections of hydrographic and ADCP data will allow freshwater transports to be calculated along the EGC, while d18O measurements will be used to distinguish between freshwater from melting sea ice and freshwater which once fell as precipitation.