| 摘 要： | The global monsoon(GM) comprises two major modes, namely, the solstitial mode and equinoctial asymmetric mode.In this paper, we extend the GM domain from the tropics to the global region and name it the global spring – autumn monsoon(GSAM), which mainly indicates a spring–autumn asymmetrical precipitation pattern exhibiting annual variation. Its distribution and possible formation mechanisms are also analyzed. The GSAM domain is mainly distributed over oceans, located both in the midlatitude and tropical regions of the Pacific and Atlantic. In the GSAM domains of both the Northern and Southern Hemispheres, more precipitation occurs in local autumn than in local spring. The formation mechanisms of GSAM precipitation vary according to the different domains. GSAM precipitation in the tropical domain of the Eastern Hemisphere is influenced by the circulation differences between the onset and retreat periods of the Asian summer monsoon, while tropical cyclone activities cause precipitation over the South China Sea(SCS) and western North Pacific(WNP). GSAM precipitation in the tropical domain of the Western Hemisphere is influenced by the tropical asymmetrical circulation between the Northern and Southern Hemispheres and the variation in the intertropical convergence zone(ITCZ) driven by the intensity of the sea surface temperature cold tongues over the equatorial eastern Pacific and eastern Atlantic. GSAM precipitation in the midlatitude domain is influenced by the differences in water vapor transportation and convergence between spring and autumn. In addition, GSAM precipitation is also affected by extratropical cyclone activities.
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