Climate control for southeastern China moisture and precipitation: Indian or East Asian monsoon?

Abstract

In this study, the water vapor sources for the precipitation processes in southeastern China (SECN) during 1981–2010 were investigated using atmospheric reanalysis data. We also studied the factors influencing the summer atmospheric moisture over SECN. These two issues are all closely related to the climate signals recorded in stalagmites recovered from caves in SECN. Result supports that the atmospheric water vapor over SECN during the whole summer time is primarily transported from the Indian Ocean. However, the vertically integrated water vapor content throughout the year in SECN has two main sources: the Indian Ocean and the tropical western Pacific. In addition, the water vapor transport for the precipitation processes in SECN has complex vertical structure. At approximately 700 hPa to 500 hPa, part of the water vapor for the precipitation in SECN comes from the Arab‐Caspian region. Finally, the water vapor content over SECN is regulated primarily by both the Indian and East Asian monsoons. Further analysis indicated that the variability of the East Asian summer monsoon is substantially regulated by the western Pacific subtropical high, the Eurasia–Atlantic thermal conditions, as well as the large‐scale Eurasia‐Atlantic atmospheric circulation. Therefore, the SECN Cave proxies can record the signals from faraway middle and high latitude Eurasia‐Atlantic climate, besides the regional East Asian monsoon and remote Indian monsoon.