Student Seminar: Cécile Defforge

Existence of a Sea Surface Temperature threshold for the tropical cyclone genesis across ocean basins

Abstract

The mechanisms of tropical cyclone (TC) genesis are still not clear, however some environmental factors such as warm sea surface temperature (SST) are known to be favourable to TC genesis. Many studies have examined the impact of SST and considered the existence of a threshold in SST for the genesis of tropical cyclones. Whereas previous studies analyzed the global distribution of SSTs at the time of cyclogenesis, I have analyzed each basin separately. Interestingly, the distributions are very close to normal distributions, with different values of the mean and standard deviation in each basin. The symmetrical shape of the probability density function, as well as the similarity to the distribution of temperature at ocean basins’ surface for the entire summer season, suggests that the concept of threshold may not be relevant.