Kevin E Trenberth
National Center for Atmospheric Research
The water and energy budgets of hurricanes and implications for climate change
Room 811 AOSS, Tuesday, April 24, 2007, Time TBA
Abstract
Based on simulations of hurricane Katina in August 2005 with the advanced Weather and Research Forecasting (WRF) model at 4 km resolution without parameterized convection, empirical relationships are computed between the maximum simulated wind and the surface fluxes and precipitation, and provide a reasonable fit to the data. The best track dataset of global observed tropical cyclones is used to estimate the frequency that storms of a given strength occur over the globe after 1970. Changes over time reflect basin differences and a prominent role for El Niņo, and the most active period globally was 1989 to 1997. Strong positive trends from 1970 to 2005 occur in these inferred surface fluxes and precipitation arising from increases in intensity of storms and also higher SSTs but their reality depends on the uncertain database. Nonetheless this work highlights the importance of surface energy exchanges in global energetics of the climate system and indicates that climate models are markedly deficient by not adequately representing tropical cyclones.
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