全球增暖背景下大气经向热量输送气候变化特征  

Climate Change Characteristics of Atmospheric Meridional Heat Transport Under Global Warming

作　　者：李张瑞 余锦华[1] 李青青 纪源 Li Zhangrui;Yu Jinhua;Li Qingqing;JI Yuan(School of Atmospheric Sciences, Nanjing University of Information Science and Technology, Nanjing 210044, China;School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, China)

机构地区：[1]南京信息工程大学大气科学学院,江苏南京210044 [2]南京信息工程大学大气物理学院,江苏南京210044

出　　处：《中国海洋大学学报（自然科学版）》2022年第5期9-18,共10页Periodical of Ocean University of China

基　　金：国家重点研究发展计划项目(2018YFC1507704);南京信息工程大学大学生创新创业训练计划项目(202010300051Y)资助

摘　　要：基于1979—2019年ERA5月平均资料,采用信息流和线性回归分析大气经向热量输送(Atmospheric heat transpont, AHT)线性趋势,并讨论全球增暖和Hadley环流对AHT的影响程度。结果表明:AHT在南北半球各纬度带及不同季节表现出不同的变化特征:6—8月,15°N—65°N和35°S—60°S分别呈现向北输送减弱和向南输送增强的趋势,12—2月,5°N—15°S和15°N—40°S分别呈现向北输送增强和向南输送减弱的趋势,表明从夏半球向冬半球的AHT净通量有增加的趋势。信息流显示,经向不均匀增暖是北半球夏季向极AHT减弱的原因。南半球冬季,Hadley环流边界南移导致潜热在副热带的辐散中心南移,感热在副热带的辐散中心南移与环流边界南移相互反馈。北半球春(秋)季,感热向赤道辐合增强(减弱)与Hadley环流增强(减弱)相互反馈。南半球春季,Hadley环流增强导致位能向副热带辐合增强,南半球秋季,Hadley环流增强导致潜热向赤道辐合增强。Based on the ERA5 monthly averaged data from 1979 to 2019, this study analyzes the climate tendency rates of atmospheric meridional heat transport (AHT) using information flow and linear regression and discusses the influences of global warming and the Hadley cell on AHT. Results indicate that AHT shows different variation characteristics in different latitudes and seasons in the Northern Hemisphere (NH) and Southern Hemisphere (SH). From June to August, a weakening of poleward transport is found between 15°N—65°N, with an intensification of poleward transport between 35°S—60°S. From December to February, an increase in northward transport is observed between 5°N—15°S, with a decrease in poleward transport between 15°S—40°S, indicating net AHT fluxes increasing from the Summer Hemisphere to the Winter Hemisphere. Information flow shows that uneven longitudinal warming is the key reason for the weakening of poleward AHT in the NH summer. In the SH winter, the southward shift of the Hadley cell leads to the southward movement of latent heat in the subtropical divergence center. The southward movement of the boundary of the Hadley cell interacts with the sensible heat near the subtropical divergence center. In the Northern Hemisphere spring (autumn), the strengthening (weakening) Hadley cell and the strengthening (weakening) equatorward convergence of sensible heat are mutually influenced. In the Southern Hemisphere spring, the enhanced Hadley cell leads to enhanced subtropical convergence of potential energy. The enhanced Hadley cell leads to enhanced equatorial convergence of latent heat in autumn.

关 键 词：经向热量输送 全球增暖 HADLEY环流 信息流 热带扩张 

分 类 号：P467[天文地球—大气科学及气象学]