Abstract

In the fall of 2004, four hurricanes, three strong ones, ravaged the Southeast United States. This year to date, 18 tropical storms have developed in the Atlantic including Category 5 storms Katrina and Rita. Given the increased activity, it is natural to ask whether this could be due to global warming. In this seminar, my modeling research with Tom Knutson at GFDL will be summarized and how they fit into the overall picture of the potential impact of global warming and hurricanes.

One limitation of the nested hurricane model-based approaches of previous modeling studies has been that the tropical climate states (present-day and high CO2) used as input to the hurricane model simulations have been derived from a single global climate model--the GFDL R30 coupled model. Also a single version of the GFDL hurricane model has been used to simulate the hurricane behavior. Hurricane simulations are known to be sensitive to parameterizations of moist physics. Our previous studies have found that idealized hurricanes, simulated under warmer, high CO2 conditions, are more intense and have higher precipitation rates than under present-day climate conditions. The present study explores the sensitivity of this result to the choice of climate model used to define the CO2-warmed environment and to the choice of convective parameterization used in the nested regional model that simulates the hurricanes.

Light refreshments are served in the Interaction Area (4th floor of the Oceanography/Physics Building) at 4:00 p.m.

All seminars begin at 3:00 p.m. and are held in room 200 of the Oceanography/Physics building.