AUTHOR=Sun Yang , Shan Xing , Zhou Shunwu , Wang Meirong , Wang Chuanhui , Deng Zhongren 

TITLE=Impacts of Tibetan Plateau sensible heat and El Niño–Southern Oscillation on precipitation over South China under the background of the PDO

JOURNAL=Frontiers in Environmental Science

VOLUME=Volume 11 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/environmental-science/articles/10.3389/fenvs.2023.1156206

DOI=10.3389/fenvs.2023.1156206

ISSN=2296-665X

ABSTRACT=Abstract: This study aims to investigate the impact of spring sensible heat (SH) over Tibetan Plateau (TP) and El Niño-Southern Oscillation (ENSO) in preceding wintertime on midsummer (July-August) precipitation over South China under the different Pacific Decadal Oscillation (PDO) phase. More specifically, eight classifications are adopted at the demarcation point around 1996 when the spring SH over TP and the midsummer precipitation in South China occurred as well as the phase transition of PDO, including positive and negative SH and ENSO under positive PDO phase (1979-1996) and negative PDO phase (1997-2019) respectively based on the Niño-3 index and spring SH calculated from 48 stations over the central and eastern parts of the TP. The results show that both the spring SH and ENSO in preceding wintertime have a significant impact on the midsummer precipitation over South China, that is, when the two factors are in their respective positive (negative) phase, the midsummer precipitation in South China is generally less (more). Importantly, the phase change of background field PDO can significantly enhanced the effect of SH and ENSO on summer precipitation over South China. Moreover, compared with the preceding wintertime ENSO, the spring SH over TP contributes more to the midsummer precipitation in South China based on analyses of their independent and synergistic effects. The main mechanism, responsible for the anomalous midsummer precipitation over South China, is the combined effects of the South Asian High (SAH) and the Western Pacific Subtropical High (WPSH), which is controlled by the spring SH anomaly over TP and ENSO, respectively. Deep understanding of the dominant factors of the midsummer precipitation over South China will help understand the local climate change and reduce the losses caused by drought and flood disasters.