The Characteristics of the Yangtze Flooding During 1998 and 2020 Based on Atmospheric Water Tracing

Abstract

Abstract The June‐July Yangtze flooding in 1998 and 2020 drew incredible attention owing to the extreme precipitation events and devastating societal/economic damages. However, the quantitative estimation of the moisture transport mechanism is intensely discussed but still unresolved. Here we investigated two events from a unique perspective of Eulerian atmospheric water tracers that tries to explain the two events from model physics. The results showed that the moisture supplies from the Northwest Pacific decreased despite of different inducements, whereas the southwest summer monsoon (SWSM)‐related moisture supplies exhibited conspicuous enhancements in both events, suggesting that the SWSM‐related moisture supplies controlled the occurrence of Yangtze flooding. The physical processes of the two events were further compared. The 2020 flooding was more severe than the 1998 event, which was related to the stronger advective convergences and in‐stratus condensations of the SWSM‐related moisture.