EGU23-6758, updated on 09 Jan 2024
EGU General Assembly 2023
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

The Decadal Variation of Eastward-Moving Tropical Cyclones in the South China Sea During 1980–2020

Xi luo1, Lei Yang2,3, Sheng Chen2,3, Dong Liang1, Johnny C. L. Chan1,4, and Dongxiao Wang1
Xi luo et al.
  • 1Sun Yat-Sen University, School of Marine Sciences, China (
  • 2State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
  • 3Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
  • 4School of Energy and Environment, City University of Hong Kong, Hong Kong, China

The track of tropical cyclones (TCs) formed in the South China Sea (SCS) can be divided into eastward and westward directions. Significant decadal variation during 1980–2020 only exists in the number of eastward-moving TCs, especially during July–September, with 47% TCs moving eastward during 1994–2004 (Period II), 22% during 1980–1993 (Period I) and only 15% during 2005–2020 (Period III). This decadal change is related to the zonal shift of Western Pacific Subtropical High (WPSH). An eastward-retreated WPSH during 1994–2004 leads to upward motion and westerly flow anomaly over the northern SCS, and therefore favors TC genesis and eastward motion. The eastward-retreated WPSH is associated with a warm sea surface temperature anomaly over the tropical western-central Pacific which induces a cyclonic flow and weakens the WPSH. With the weaker modulation of WPSH, stronger intraseasonal oscillation (ISO) in the SCS during Period II favors eastward-moving TCs due to the westerly flow associated with the ISO.

How to cite: luo, X., Yang, L., Chen, S., Liang, D., Chan, J. C. L., and Wang, D.: The Decadal Variation of Eastward-Moving Tropical Cyclones in the South China Sea During 1980–2020, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6758,, 2023.