Surface temperature dependence of the frequency of severe storms in the tropical oceans 1

The analysis of five years of data from the Atmosph eric Infrared Sounder (AIRS) shows that the frequency of extreme Deep Convective Clouds (DCC) in the tropical oceans increases by about 50% per 1 K of warming of the zonal mean surface temperature. With the current 0.13K/decade rate of global warming a 6%/decade increase in the frequency of DCC and, through correlation, severe storms, can be expected. Since we define ext reme DCC as deep convective clouds with cloud top temperature of 210 K or colder, i.e. clou ds which penetrate the tropopause and inject water vapor into the lower stratosphere, an increas e in the frequency of DCC with global warming also increases the amount of water vapor in the stratosphere. This increase is consistent with observations over the past 50 years.