Decreasing precipitation extremes at higher temperatures in tropical regions

Abstract

It has been often accepted that rising troposphere temperatures will lead to higher precipitation intensities. This argument is based on the Clausius-Clapeyron (C-C) relation, which indicates an increase in atmospheric moisture storage capacity of approximately 7 % K -1. However, recent studies carried out in mid-latitude regions indicate that changes in precipitation intensity as a function of temperature do not necessarily follow the C-C relation. This study aimed to evaluate the correlation between precipitation extremes and temperature in tropical regions, using measured data obtained at low latitude ranges over Brazil. The results indicate that, at daily timescale, the C-C relation alone is unlikely to explain the relation between precipitation extremes and temperatures in tropical regions. Additional aspects, such as moisture availability and the duration of precipitation events, should be further analyzed to allow a comprehensive understanding of the relationship between temperature and precipitation intensity. Moreover, we show that in tropical regions, higher temperatures may reduce the magnitude of extreme precipitation events at daily timescales, independent of the season of the year. ©g 2012 Springer Science+Business Media B.V.