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Abstract

In the Northwestern Pacific, the meridionally propagating Rossby waves known as the Pacific-Japan (PJ) pattern is the dominant teleconnection pattern in the vicinity in East Asia, and it often accompanies heatwaves. In this study, the circulation and thermodynamic characteristics of the pattern was investigated based on a daily timescale to better understand their relationship with the likelihood of heatwaves/marine heatwaves in East Asia. According to thermodynamic budget calculations, horizontal heat advection crossing the climatological flow pattern is the key factor for the observed surface air warming. For the ocean warming, the increased solar radiation due to anti-cyclonic circulation is the most impact factor over the East Asia. The CESM2 simulation results show that the heat forcing in the tropical western Pacific and atmospheric/marine heatwaves over East Asia is closely relevant the meridionally propagating Rossby waves.