AUTHOR=Yang Ke , Liu Chunlei , Cai Jiaxi , Cao Ning , Liao Xiaoqing , Su Qianye , Jin Liang , Zheng Rong , Zhang Qingkui , Wang Lu 

TITLE=The north–south shift of the ridge location of the western Pacific subtropical high and its influence on the July precipitation in the Jianghuai region from 1978 to 2021

JOURNAL=Frontiers in Earth Science

VOLUME=Volume 11 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2023.1251294

DOI=10.3389/feart.2023.1251294

ISSN=2296-6463

ABSTRACT=The Jianghuai region is the area between Yangtze river and Huai river in China and is a densely populated agriculture region in China, therefore the economics and human activity there are significantly affected by the precipitation changes, particularly during the summer when extreme storms and droughts normally occur. It will be helpful if the summer precipitation changes can be predicted. The monthly ERA5 atmospheric reanalysis data from 1978 to 2021 is employed in this study to investigate the relationship between the ridge latitudinal location of the western Pacific subtropical high (WPSH) and the precipitation in July over the Jianghuai region. Results show that the WPSH ridge location has an important impact on the amount and spatial distribution of the precipitation in this region. When the ridge was northward, an anomalous anticyclonic circulation will appear over the western Pacific, leading to the weakening of the summer monsoon and the reduction of moisture transport from the Indian Ocean, and therefore the decreasing precipitation in Jianghuai region, while the situation is opposite when the ridge was southward. The Niño 3.4 index in March and the India-Burma trough intensity index in June have significant correlations with the July WPSH ridge location, and both can be used as precursors to predict the WPSH ridge location and therefore the precipitation in this region.