Global scaling of precipitation extremes using near-surface air temperature and dew point temperature

Global warming has altered the energy budget and water cycle processes of the land-atmosphere system, which has resulted in significant effects on precipitation extremes. Previous studies have identified a hook structure between near-surface temperature and precipitation extremes, in which extremes increase with temperature rises and decline thereafter. However, the underlying physical mechanisms of this association remain poorly understood. In this study, global-scale responses of precipitation extremes to near-surface air temperature (SAT) and dew point temperature (DPT) were quantified using the ERA5 reanalysis dataset. The results reveal a hook structure between precipitation extremes scaling and temperature, for both SAT and DPT, over many regions worldwide. The peak point temperature (T (pp)) ranges from 15 degrees C to 25 degrees C, increasing as latitude decreased. The association of precipitation extremes with SAT is negative in many areas in the tropics, whereas that with DPT is almost always positive; this suggests that moisture supply is the main factor limiting precipitation at higher surface temperatures. The hook structure and scaling rates incompatible with Clausius-Clapeyron scaling are associated with various factors including precipitation duration, total column water vapour, convective available potential energy, and relative humidity.

Automated summary

Global warming has significantly impacted precipitation extremes by altering the energy budget and water cycle of the land-atmosphere system. This study quantifies the global-scale responses of precipitation extremes to near-surface air temperature and dew point temperature using the ERA5 reanalysis dataset. The results reveal a "hook" structure between precipitation extremes and temperature, with various factors influencing this relationship.