Extended Abstract (524K)1C.8
Could hurricanes form from random convection in a warmer world?
David S. Nolan, University of Miami, Miami, FL; and E. D. Rappin and K. A. Emanuel
In our present day climate, hurricanes are believed to occur only through a "finite amplitude instability," which is to say that a precursor disturbance (such as an easterly wave) of sufficient strength is required for tropical cyclogenesis. The likelihood of tropical cyclogenesis is also known to increase as the local sea surface temperature (SST) increases, as shown by some modeling studies and statistical analyses of genesis locations. Using the WRF model, we have explored the sensitivity to SST of the threshold disturbance strength for cyclogenesis in idealized, three-dimensional, cloud-resolving simulations of convection in equilibrium over warm oceans. Preliminary results have shown that if SSTs are high enough, cyclones can form spontaneously. The boundary between these subcritical and supercritical regimes will be explored.
Session 1C, Tropical Cyclones and Climate I - Theory and Modeling
Monday, 24 April 2006, 8:00 AM-9:45 AM, Regency Grand Ballroom
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