German Polarstern Expedition Finds Antarctic Deep Sea Turns Colder
22.04.2008 - Logistics, Other
First results from the 2007-08 Polarstern expedition of the Alfred Wegener Institute (AWI) for Polar and Marine Research reveal that the Antarctic deep sea is getting colder and that this could possibly stimulate the circulation of the oceanic water masses.
The objective of the Polarstern expedition was to study the oceanic circulation of the Southern Ocean and the oceanic cycles of materials which depend on the oceanic circulation. Deployed within the International Polar Year, two projects researched ocean currents, temperature distribution, salt content and trace substances in the Antarctic sea water:
- CASO (Climate of Antarctica and the Southern Ocean)
- GEOTRACES (International study of the biogeochemical cycles of Trace Elements and Isotopes in the Arctic and Southern Oceans)
An important finding within the GEOTRACES framework was the discovery of the smallest iron concentrations ever recorded in the ocean. Iron concentration is an important parameter used in determining the ocean's capacity to act as a carbon sink. This is because iron is an essential trace element for algae growth, an organism which absorbs CO2 content from the air.
While the previous Arctic summer was the warmest ever, sea ice in the Southern Ocean reached its maximum due to a particularly cold summer this season. The sinking water masses in the Southern Ocean play a major role in global climate as part of the region's water overturning process. The Polarstern expedition will contribute understanding about these opposing Arctic and Antarctic developments. However, autonomous measuring buoys will have to be deployed over the future in order to determine whether the cold Antarctic summer is part of a new trend or whether it was just an isolated event.
