人类活动会导致Hadley环流（HC）边界向极扩张，使极端天气、气候事件更频繁，开展人类活动对HC边界向极扩张贡献及机理的研究具有重要科学意义。以往研究主要关注全球纬向平均HC边界的变化，关于局地HC边界变化的研究较少。同时，在纬向方向上海陆分布不均匀，使得不同区域局地HC边界变化和全球纬向平均HC边界变化可能不同，并且人类活动对不同季节、不同区域局地HC边界向极扩张的贡献及机理还不明确。因此，本项目拟采用多套再分析资料和CMIP5/CMIP6提供的不同历史气候模拟试验，（1）研究季节平均局地HC边界向极扩张的特征及它们对人类活动的响应特征；（2）利用最优指纹法分析人类活动对局地HC边界向极扩张的贡献；（3）利用全球大气环流三型分解方法探究科氏力项、平流输送项、耗散项和径向温度梯度项的作用，揭示局地HC边界向极扩张的物理机制，旨在进一步科学认识人类活动在局地HC边界向极扩张中的贡献及机理。

Anthropogenic activities have led to poleward expansion of the Hadley circulation (HC), which can result in more extreme weather and climate events. It has great importance to study the contribution of the anthropogenic activities to the poleward expansion of the HC edge and related physical mechanisms. Previous studies focused mainly on the changes of the global zonally averaged HC edge, and the researches on the changes of the regional zonally averaged HC edge are rare. Meanwhile, as land, sea, and topography are not evenly distributed in the latitudinal direction, changes in the regional HC edge may be different from those in the global zonally averaged HC edge. In addition, the contributions of the anthropogenic activities to the poleward expansion of the regional HC edge and related physical mechanisms in different seasons and regions are unknown. Therefore, using the reanalysis data sets and different historical simulations provided by the CMIP5/CMIP6, (1) we analyze the characteristics of the poleward expansion of the seasonal and regional HC edge and their response to the anthropogenic activities; (2) we study the contribution of the anthropogenic activities to the poleward expansion of the regional HC edge by using the optimal fingerprinting technique; (3) we explore the effects of the Coriolis force term, advection term, dissipation term, meridional air temperature gradient term by using the three-pattern decomposition of the global atmospheric circulation, and further reveal the physical mechanisms of the poleward expansion of the regional HC edge. The purpose of this project is to provide a scientific understanding of the contribution of the anthropogenic activities to the poleward expansion of the regional HC edge and related physical mechanisms.