摘要
The Yangtze River Basin(YRB;27°N-36°N,100°E-123°E)enters its main rainy season,known as Meiyu[1,2],normally from mid-June to mid-July,along with the northward seasonal march of East Asian monsoon precipitation.The seasonal evolution of the YRB rainfall is closely tied to the location of subtropical westerlies relative to the Tibetan Plateau.The mechanical forcing of westerlies impinging on the large-scale topography can generate meridional wind convergence downstream,inducing rainfall over the downstream regions[3,4].From spring to summer,the westerlies core undertakes a notable northward migration,moving from the south of the plateau to directly above the plateau[5].Correspondingly,the downstream convergence and moisture supply gradually intensify,leading to the northward migration of the rain belt and the onset of Meiyu[4,5].The YRB rainfall is fundamentally governed by the evolution of moisture and atmospheric circulation.Under global warming,both dynamical effects associated with circulation changes and thermodynamic effects affected by moisture changes can substantially modulate the Meiyu onset.
基金
jointly supported by the National Natural Science Foundation of China(42175029,42475029 and 92358302)
Laoshan Laboratory(LSKJ202300302).
