EGU General Assembly 2020
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

The relative roles of the South China Sea summer monsoon and ENSO in the Indian Ocean dipole development

Jianping Li1,2, Yazhou Zhang3, Jiaqing Xue4, Fei Zheng5, Renguang Wu6, Kyung-Ja Ha7,8, and Juang Feng3
Jianping Li et al.
  • 1Key Laboratory of Physical Oceanography/Institute for Advanced Ocean Studies/Frontiers Science Center for Deep Ocean Multispheres and Earth System (DOMES), Ocean University of China, 266100 Qingdao, China.(
  • 2Laboratory for Ocean Dynamics and Climate, Pilot Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
  • 3College of Global Change and Earth System Science (GCESS), Beijing Normal University, Beijing 100875, China
  • 4Key Laboratory of Meteorological Disaster of Ministry of Education, Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Institute for Climate and Application Research (ICAR), Nanjing University of Information Science an
  • 5State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
  • 6School of Earth Sciences, Zhejiang University, Hangzhou 310027, China
  • 7Center for Climate Physics, Institute of Basic Science, Busan, South Korea
  • 8Department of Atmospheric Sciences, Pusan National University, Busan, South Korea

The influence of El Niño-Southern Oscillation (ENSO) on the Indian Ocean Dipole (IOD), a coupled ocean–atmosphere mode of interannual climate variability, has been widely investigated over recent decades. However, a latest study indicates that the South China Sea summer monsoon (SCSSM) might also be responsible for IOD formation. Furthermore, an abnormal SCSSM does not always coincide with ENSO during boreal summer (June–August, JJA); consequently, the individual and combined effects of the SCSSM and ENSO on the IOD remain elusive. This study shows that the amplitude of the IOD tends to be much stronger under the coexistence of SCSSM and ENSO than that under individual SCSSM or ENSO events during JJA and autumn. The findings also indicate that the SCSSM and ENSO play the dominant role around the eastern and western poles of the IOD, respectively. An anomalous local Hadley circulation closely related to the stronger SCSSM favors anomalous southeasterly of Sumatra and Java during JJA, which enhance oceanic upwelling and subsequently result in cooling of the sea surface temperature (SST) over this area. Similarly, it can be envisaged that the contemporaneous ENSO could influence JJA SST anomalies over the western Indian Ocean via the Walker circulation coupled with oceanic variations.

How to cite: Li, J., Zhang, Y., Xue, J., Zheng, F., Wu, R., Ha, K.-J., and Feng, J.: The relative roles of the South China Sea summer monsoon and ENSO in the Indian Ocean dipole development, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1819,, 2019