The role of the tropics in the Ice Ages
A Department of Atmospheric and Oceanic Sciences & Department of Earth and Space Sciences joint seminar presented by Dr. David Lea, Professor, Department of Earth Science, University of California Santa Barbara
Wednesday, November 06, 2013
In the last 15 years, a wealth of information has become available from tropical climate records spanning the Ice Ages. These records indicate a very active role for the tropics in the progression of the Ice Ages. For example, warm pool waters cooled by about 3 °C during the Ice Ages, and tropical SST changes often preceded changes in ice extent. High resolution glacial and deglacial records reveal that the Indian, Asian and West African monsoon were much weaker during the Last Glacial Maximum (23-19 kyr BP), that the deglaciation (19-11 kyr BP) was punctuated by two prominent weak monsoon intervals, and that the monsoon was much stronger during the early Holocene (11-8 kyr BP). This progression of changes in the monsoon system was likely driven by changing boundary conditions and insolation, as well as ITCZ shifts linked to rapid climate change in the North Atlantic region. Results from a coupled model simulation of the LGM climate suggest that profound changes in Indian Ocean coastal circulation can account for some of the observed regional changes.
SEMINAR TEA: 4:30-5:00PM (MSB 7124B)