The instruments have been deployed beginning of July during an expedition of Research Vessel Polarstern. The gliders with a length of two meters repeatedly dived to 1000 m depth along given sections and measured temperature, salinity and oxygen on the way. When reaching the surface the data were send via satellite to the AWI in Bremerhaven. Thus the scientists have access to the data in real time. This way of communication was used by the scientists to adjust the cruise track – for example when the glider was approaching the ice-edge off Greenland.
The data, gathered during the mission, will be used by Katrin Latarius, to analyze the effect of increasing freshwater in the near-surface layer of the Arctic on the deep water renewal in the Nordic Seas. Backgrounds of this question are changes in the climate of the Arctic Ocean: Sea-Ice melt, elevated river-runoff as well as precipitation lead since the 1990th to increased near-surface freshwater content in the Arctic. From there the freshwater spread out in direction to the North Atlantic. As freshwater stabilizes the stratification in the water column, it hampers the sinking of cooled water to great depths. Thus the scientists from AWI assume, more freshwater will also reach the inner Nordic Seas and will hamper the deep water ventilation there. First results are expected in the coming weeks.
Source: The Arctic Journal, http://arcticjournal.com