Why Is East Asian Summer Monsoon Circulation Enhanced Under Global Warming?

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The near-surface southerly wind is a key feature of East Asian summer monsoon (EASM) circulation, and a stronger EASM circulation leads to a northward shift of East Asian rainfall. Almost all climate models show an enhanced EASM circulation in a warmer climate, and previous studies attributed the enhanced EASM to the enhanced zonal land-sea thermal contrast.

The near-surface southerly wind is a key feature of East Asian summer monsoon (EASM) circulation, and a stronger EASM circulation leads to a northward shift of East Asian rainfall. Almost all climate models show an enhanced EASM circulation in a warmer climate, and previous studies attributed the enhanced EASM to the enhanced zonal land-sea thermal contrast.

"However, the land-sea thermal contrast cannot explain the seasonality of the change in East Asian circulation." said Dr. HE Chao from Jinan University, "What's more, the enhanced EASM circulation is associated with a large-scale cyclone anomaly around Tibetan Plateau (TP), motivating us to hypothesize that TP may play a certain role".

In a recent study published in Journal of Climate, Dr. HE Chao and Prof. ZHOU Tianjun from Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences, in cooperation with Dr. WANG Ziqian from Sun Yat-sen University and Prof. Tim Li from Nanjing University of Information Science and Technology, confirmed this hypothesis. The study shows that the TP plays an essential role in enhancing the EASM circulation under global warming through enhanced latent heating over the TP.

Read more at Institute of Atmospheric Physics, Chinese Academy of Sciences

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