Heat flux in Fram Strait affects Arctic climate
Fram Strait is a deep sea channel connecting the Arctic Ocean and the Nordic Seas. Lying between Greenland and the island of Spitsbergen, it represents the main point of entry for warm water from mid-latitudes to the Arctic Ocean. Heat flux has been measured in this area for over 20 years by a series of moored instruments. Researchers from the ASOF-N project have continued this work. They have monitored the changes in temperature and velocity of water passing through the strait in an attempt to understand how it varies over time. Since 2001 measurements of heat flux have been complemented by Acoustic Doppler Current Profiler (ADCP) recordings. These have been taken by research vessels which have delivered highly detailed information on temperature and velocity. Hydrographic measurements have also been taken to determine heat flux. The combination of these three observational methods, which had never been published before, allowed the most accurate estimates possible to be made for heat transport. The current of warm water through the Fram Strait splits into various branches which travel northward and eastward or recirculate immediately back into the strait. The size and strength of these different branches need to be determined as they affect the amount of oceanic heat entering the inner Arctic Ocean. The likelihood of error was considerably reduced by the research team by deploying additional moorings in the central part of the strait. Improvements to the Alfred Wenger Institute's North Atlantic-Arctic Ocean-Sea Ice Model (NAOSIM) enabled the different branches of warm water to be represented more realistically. The models employed meteorological data, simulating its impact on sea ice, currents, temperature and salinity in the ocean. Close agreement between the model and estimates based on observations from Fram Strait have enabled the ASOF-N team to relate changes in the channel to large-scale oceanic developments.
