The Role of Ocean Eddies in Large-Scale Global Climate Variability



03/18/2016 - 12:00pm to 03/19/2016 - 11:45am


Ben Kirtman

Current IPCC coupled climate models are generally unable to resolve mesoscale ocean features that are essential for capturing realistic ocean heat transport, coupled ocean-atmosphere interactions and their consequent impacts on regional climate. We use the Community Climate Systems Model (CCSM4) with a one-tenth degree ocean component and find seasonal-to-decadal variability climate phenomenon that are otherwise not represented in current IPCC-class models. For instance, on seasonal-to-intraannual timescales, we find that a retreated Loop Current within the Gulf of Mexico is related to reduced precipitation over southern continental US but enhanced precipitation over the Intra-Americas Seas (IAS) and Caribbean islands. This may be due to better resolved Caribbean Current bringing warm tropical waters into the IAS and supporting convective precipitation. On interannual timescales, we identify a tropical-subtropical oceanic teleconnection between SST over the Agulhas leakage and wind stress curl over tropical Indian Ocean associated with ENSO. This suggests the use of ENSO as a predictor for Agulhas leakage interannual variability and possibly the Atlantic meridional overturning circulation. On decadal timescales, we find North Atlantic variability that is completely absent in the IPCC class model, which has implications on precipitation over continental US and Europe.

Short Bio:
Professor Kirtman received his BS in Applied Mathematics from the University of California-San Diego in 1987, and his MS and Ph.D. in 1992 from the University of Maryland-College Park. From 1993-2002,
Dr. Kirtman was a research scientist with the Center for Ocean-Land- Atmosphere Studies and in 2002 joined the faculty of George Mason University as a tenured Associate Professor. In 2007, Dr. Kirtman moved to the University of Miami Rosenstiel School of Marine and Atmospheric Science as a full professor of meteorology and physical oceanography, and serves as the Program Director for Climate and Environmental Hazards at the Center for Computational Science. From 20011-2015 Ben was the Associate Dean of Research for the Rosenstiel School. In December 2015 he was appointed as the Director of the Cooperative Institute for Marine and Atmospheric Studies. Kirtman has published over 120 peer-reviewed papers on climate variability and prediction from day to decades.