The focus of this project is the study of rapid climate change driven by changes in sea ice extent in the North Atlantic and Arctic oceans, motivated by Dansgaard-Oeschger (D-O) events recorded in the Greenland ice cores. A recent modeling study suggests that a modest reduction in sea ice can account for the abrupt changes in temperature and snow accumulation recorded in the Greenland ice core.
The science questions which this project will address are: 1) Why did the sea ice extent change suddenly; 2) Why did the new state persist for several centuries before gradually collapsing back to its original glacial state; and 3) How does this explain abrupt climate changes elsewhere?
The investigators will be guided in their research by the hypothesis that abrupt reconfigurations in the coupled tropical climate system are long-lived and influence the climate outside of the tropics via teleconnections through the atmosphere or ocean circulation, requiring only a modest change in the thermohaline circulation to drive sea ice changes that cause the large rapid climate changes recorded in Greenland.
Graduate and undergraduate students are to play major roles in this project, and the results will influence courses taught by the investigators in oceanography, climate and climate change, climate modeling, and applied math. The project also represents a collaboration between climate dynamicists, paleoclimate data experts, and climate modeling experts, providing a solid cross-disciplinary approach to address a fundamental paleoclimate issue. The synergy of climate modeling and proxy data is expected to prove useful in guiding future model development.
