COG3

Graduate Student: Scripps Institute of Oceanography
Title: Was there a Little Ice Age in Antarctica? Temperature and precipitation history at the West Antarctic Ice Sheet Divide for the last thousand years
Abstract: The climate of the last 1000 years is often referred to in terms of the “Medieval Warm Period” and “Little Ice Age”, which reflect a Euro-centric view of the world. In our effort to understand the mechanisms for large scale multi-decadal climate variability, we need data from every part of the globe. Whether or not regional cooling in the North Atlantic region during 1400-1850 C.E. was accompanied by Antarctic cooling strongly constrains the mechanisms of this cold anomaly.
New results from the West Antarctic Ice Sheet divide shows evidence for a long term cooling trend between 1400 and 1800 C.E. with a minimum in the mid Eighteenth century of about -1°C, which is similar in amplitude to the maximum cooling at Greenland Summit. This result is consistent with the idea that decreased solar activity is the root cause of this widespread cooling. However, at shorter timescales, there are some anti phased oscillations of the surface temperature record between Greenland and West Antarctica. The origin of these ~50 year oscillations remains to be established.