Global observational evidence of strong linkage between dew point temperature and precipitation extremes

Abstract

Using global station?based observations of precipitation, near?surface air temperature (SAT), and dew point temperature (DPT), we show that the negative scaling relationship found between extreme daily precipitation and SAT over the tropics is associated with the low seasonality in temperature. When using a binning technique or quantile regression, not accounting for seasonality in temperature produces a negative scaling for the majority of stations in the tropics, with higher temperatures associated with smaller precipitation extremes. After removing temperature seasonality, we find that most locations show a positive (median 5.2%/K) scaling with SAT and 96% of global locations exhibit positive (median 6.1%/K) scaling with DPT. Moreover, about 33% (22%) of the locations show super C?C scaling (higher than 7%/K) with DPT (SAT). Our results show that the impact of warming on extreme precipitation (especially over the tropics) may be higher than previously thought.