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

Frontiers in Environmental Science

Environmental Science

Chuanhui Wang¹  Yang Sun²  Meirong Wang²  Zhongren Deng²  Shunwu Zhou²  Xing Shan³ 

[1] Anhui Public Meteorological Service Center, Hefei, Anhui, China;Key Laboratory of Meteorological Disaster, Ministry of Education (KLME), Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Joint International Research Laboratory of Climate and Environment Change (ILCEC), Joint Center for Data Assimilation Research and Applications, Nanjing University of Information Science and Technology, Nanjing, China;Shandong Meteorological Bureau, Weihai, Shandong, China;

关键词: sensible heat;    Tibetan Plateau;    ENSO;    midsummer precipitation;    South China;   

DOI  :  10.3389/fenvs.2023.1156206

 received in 2023-02-01, accepted in 2023-03-24,  发布年份 2023

来源: Frontiers

【 摘 要 】

This study aims to investigate the impacts of the spring sensible heat (SH) over the Tibetan Plateau (TP) and the El Niño–Southern Oscillation (ENSO) in the preceding wintertime on midsummer (July–August) precipitation over South China under the different Pacific decadal oscillation (PDO) phases. More specifically, eight classifications are adopted at the demarcation point around 1996 when the spring SH over the TP and the midsummer precipitation in South China occurred as well as the PDO phase transition, including positive and negative SHs and ENSOs under a positive PDO phase (1979–1996) and a negative PDO phase (1997–2019), respectively, based on the Niño-3 index and the spring SH calculated from 48 stations over the central and eastern parts of the TP. The results show that both the spring SH and the 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 enhance the effect of the SH and the ENSO on summer precipitation over South China. Moreover, compared with the preceding wintertime ENSO, the spring SH over the 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 are the combined effects of the South Asian high (SAH) and the western Pacific subtropical high (WPSH), which are controlled by the spring SH anomaly over the TP and the 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.

【 授权许可】

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Copyright © 2023 Sun, Shan, Zhou, Wang, Wang and Deng.