EGU23-5908
https://doi.org/10.5194/egusphere-egu23-5908
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Variations of Summer Extreme and Total Precipitation over Southeast Asia andAssociated Atmospheric and Oceanic Features

Lianlian Xu
Lianlian Xu
  • Sun Yat-sen University, School of Atmospheric Sciences, China (xullian@mail.sysu.edu.cn)

Southeast Asia lies at the heart of heavy precipitation on Earth, and a large amount of latent heat released
here provides substantial energy for the global atmospheric circulation. Utilizing gauge-based daily precipitation and the
self-organizing map technique, the summertime extreme and total precipitation over Southeast Asia during 1979–2019 are
classified into three and five distinct patterns, respectively. The three extreme precipitation clusters are characterized by
southern dry and northern wet (C1_extreme), overall wet (C2_extreme), and northern dry and southern wet (C3_extreme)
structures. The frequencies of these patterns exhibit increasing trends during the analysis, although they are not statistically
significant for C1_extreme. The C1_extreme pattern is accompanied by an anomalous cyclone over the South China Sea in
response to negative Indian Ocean sea surface temperature anomalies (SSTAs). The C2_extreme and C3_extreme clusters
are characterized by a westward extension of the western Pacific subtropical high, regulated by cool SSTAs over the tropical
central-eastern Pacific that are induced by the tropical North Atlantic warming and the tropical Pacific and Atlantic
SSTAs, respectively. For total precipitation, the first and second clusters show overall dry distributions, which are mainly
composed of nonextreme precipitation. The spatial patterns and atmospheric and oceanic features associated with the
other three clusters of total precipitation bear large resemblances to those of C1_extreme, C2_extreme, and C3_extreme,
respectively, but their trends exhibit smaller similarities. Comparing the differences between extreme and total precipitation
over Southeast Asia could improve our understanding of their regional variabilities and relationships, and potentially
their global impacts.

How to cite: Xu, L.: Variations of Summer Extreme and Total Precipitation over Southeast Asia andAssociated Atmospheric and Oceanic Features, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-5908, https://doi.org/10.5194/egusphere-egu23-5908, 2023.