Role of Topographic Forcing in the Maritime Continent Region in Interaction Between the East Asian Summer Monsoon and the Australian Winter Monsoon

Abstract The topography in the Maritime Continent (MC) has significant impact on climate anomalies in the Asian‐Australian monsoons region. In the present study, the Regional Climate Model Version 4.6 (RegCM4.6) is applied for the simulation of climate over the Asian‐Australian monsoon region during the boreal summer. Results demonstrate that the RegcM4.6 is able to well reproduce precipitation, temperature and low‐level and upper‐level circulation patterns over the Asian‐Australian monsoons region. A sensitivity experiment with zero topographic height in the MC region shows that the intensity of western Pacific subtropical high (WPSH) and Australian cold high both weaken simultaneously, while the cross‐equatorial flows also decline and the East Asian‐Australian monsoons become weaker. Meanwhile, the anomalous cyclonic circulation with significant convergence prevails in lower levels over the western Pacific, leading to more precipitation and higher temperature. In the MC region, there are more precipitation and high temperature in the north while there are less precipitation and low temperature in the south. Temperature increases over a large area from the Yunnan‐Guizhou Plateau to the Loess Plateau but decreases in the southeastern coast of China and eastern India. These results have important implications for better understanding the topographic impact of the MC region on the interaction between the east Asian‐Australian monsoons.