Abstract:Based on ERA-Interim(1979-2014) reanalysis data and NCAR Community Atmosphere Model (CAM 5.1),the influences of Sea Surface Temperature Anomaly (SSTA) on the dominant modes of summer Asian subtropical westerly jet variability were explored. Firstly, by using theoretical analysis and dynamic diagnostic methods, the physical characteristics of jet domain modes were analyzed and the significant association between SSTA and the summer jet variation was confirmed. Secondly, on the basis of observation, various numerical experiments were designed to explore the specific contribution of SSTA in different regions. Results show that the first mode is closely related to the Pacific and Indian Ocean SSTA, and under their similar influences, the high-level wind field showed a zonally symmetric distribution with meridional migration along axis; the upstream and downstream wind fields of the second mode are affected by different sea surface heat source, and the synergic effect of the Indian, Pacific and North Atlantic SSTA produce a quadrupole asymmetric distribution over Asia. These results help to understand the variation characteristics of the summer Asian subtropical westerly jet more comprehensively and provide a new basis for the study of SSTA effects on jet variability.