Understanding the Origins of Abrupt Climate Change

Funding is provided to improve the understanding of abrupt climate change through data-model comparisons using paleoclimate data and a 3-dimensional coupled, global climate model of intermediate complexity, and a simple, nonlinearly coupled system of differential equations representing sea ice extent variability. At the center of the research strategy is the premise that it should be possible to anticipate long-term (centennial to millennial scale) and large amplitude abrupt climate change events. Furthermore, the researcher maintains that with the ever-increasing accuracy of climate models it eventually will be possible to have a quantitative, accurate forecast of the bounds of natural climate variability.

Specifically, the researcher will examine Dansgaard-Oeschger (DO) climatic oscillations of the last ice age recorded in ice cores from Greenland to investigate whether DO events are caused by nonlinear free oscillations of the thermohaline circulation (THC) in the ocean. These changes are, in turn, hypothesized to be externally forced by astronomically induced changes in solar insolation.