Ice sheet-ocean interaction
4 November 2015
Ocean currents play a crucial role in the Earth's climate; they spread warm waters around the oceans, from the equator to the poles. Researchers have used the grain size of deep-sea sediments to reconstruct how the strength of these currents has varied in the past. This approach relies on the sediments in the study being sorted and transported solely by ocean currents. However, repeated collapse of ice sheets in the northern hemisphere during the ice ages caused massive armadas of icebergs to float across the Atlantic Ocean. These icebergs carried with them sediment that had not been sorted, and which has confused the reconstruction of the past flow speed variability. Jonkers and his colleagues have developed a method to overcome the problem of ice-rafting when reconstructing changes in the ocean circulation, improving the reliability for studying the interaction of ice sheets and ocean in the past.
This will help to gain a better understanding of the mechanisms of abrupt climate change.