부산대학교 도서관

Based on observations, reanalysis data, and numerical experiments, the present study investigates the link between the interannual variation in precipitation over South China (SC) and the eastern Tibetan Plateau (ETP) in July during 1979–2019 and the underlying mechanisms. Results show that during May–September the variation in precipitation exhibits a dipole pattern between the two regions in July and August only, with more significance in July. The correlation coefficients of precipitation between the two regions in July and August are − 0.60 and − 0.34, statistically significant at the 99% and 95% confidence levels, respectively. The role of developing ENSO in the formation of the precipitation dipole in July is further investigated. During El Niño's development in July, precipitation increases over the tropical central–eastern Pacific, and decreases from India to the Maritime Continent and tropical Atlantic. These conditions cause anomalous cyclones over SC and the northern Bay of Bengal, and an anomalous anticyclone over Lake Balkhash to Northwest China in the middle and lower troposphere via the tropical atmospheric bridge and upper-tropospheric wave trains over Eurasia. This favors the July precipitation dipole with increased (decreased) precipitation over SC (the ETP). In La Niña's developing phase in July, the opposite is true. Moreover, numerical experiments with the ECHAM5 model can reproduce the above physical processes. [ABSTRACT FROM AUTHOR]