A NUMERICAL EXPLORATION OF THE SENSITIVITY OF TROPICAL CYCLONE RAINFALL INTENSITY TO SEA-SURFACE TEMPERATURE

It is commonly accepted that there is a monotonically increasing relat ionship between sea surface temperature (SST) and tropical cyclone int ensity (as measured by maximum near-surface winds or minimum central p ressure). This perceived relationship has been used to extrapolate the effects of climatologically warmer SSTs on tropical cyclones. These w armer SSTs are one of the consequences of doubled CO2 predicted by cli mate general circulation models (GCMs). Very few investigations have a ctually critically addressed this SST-storm intensity relationship, ho wever. In this paper, a limited area modeling study is used to explore the potential links between SST and tropical cyclone intensity. Previ ous work, including some observational data, is reviewed and its impli cations for the interpretation of the results given here is presented. Finally, the implications of the changes in SST on the thermodynamic structure of the atmosphere-in particular, the destabilization of the boundary layer-are identified as another possible mechanism of intensi fication for these modeled storms.