Increasing Difference of China Summer Precipitation Statistics Between Percentage Anomaly and Probability Distribution Methods Due to Tropical Warming

Abstract

Precipitation anomaly grades are usually defined by the percentage anomaly (Pa) or probability distribution (Pd) methods. However, the difference between the two may lead to different estimates for the same events, creating difficulty in judging the severity of the events. Here, we quantify the difference in measuring precipitation variability in China between Pa and Pd methods and analyze physical meaning and influencing factors of the difference. The results show that Pa tends to underestimate the domain of wetness (e.g., it underestimated 7.67% in June 2018) and overestimate/underestimate the severity of extreme wetness (>1.5σ)/dryness (