Seasonal characteristics and spatio-temporal variations of the extreme precipitation-air temperature relationship across China

Abstract

Abstract It is assumed that extreme precipitation (P) increases with air temperature (T) by a scaling rate close to 7%/°C without moisture limitation according to the Clausius-Clapeyron (C-C) relationship. However, the spatial distribution of the P-T relationship in China is subject to divergent conclusions including both sub-C-C (<7%/°C) and super-C-C (>7%/°C) scaling with reasons yet to be examined. Based on the long-term observations, here we show that P-T relationships with peak structure exist in most regions across China. The scaling rate in the wet season shows a decreasing spatial pattern from the southeast to the northwest, while sub-C-C scaling in the dry season dominates most regions across China. Mixing precipitation events from different seasons could lead to miscalculation of the P-T scaling rate. Furthermore, significant increases in peak precipitation at high percentiles have been observed in southern regions of China during the historical period, indicating that the peak structure does not imply a potential upper limit for precipitation extremes. Our results highlight the importance of considering seasonal characteristics in analyzing the extreme precipitation-temperature relationship in a changing climate.