Studies of the Relationship Between Southern Hemispheric Atmospheric Circulation and Climate over East Asia
有关南半球大气环流与东亚气候的关系研究的若干新进展

The Southern Hemisphere(SH) atmospheric circulation is both an important component of the global general circulation and a key factor influencing the global climate change and Asian monsoon systems.In early times,Chinese meteorologists focused the role of SH in the East Asia summer monsoon and obtain important results.Studies of the SH climate variability are currently paid much attention by meteorologists in the world.In recent years,meteorologists have been doing researches on the SH interannal variability and its association with East Asian Climate,with special focus on the Antarctic Oscillation(AAO) and the subtropical high pressure systems in SH.Besides,studies of the relationship between SH and both East Asian climate and dust during boreal winter and spring have been paid much attention as well.This paper introduces recent studies including the relationship between the interannual variability of AAO and dust weather frequency(DWF) in North China and East Asian climate during boreal winter and spring;central North China precipitation based on the reconstructed data from the Qing Dynasty;the summer rainfall over the Yangtze River valley,as well as the reproducibility of variability of AAO.Potential future research focuses are also discussed in the paper.Recent results show that the interannual variation of AAO plays a significant role in the dust-related atmospheric circulation during boreal spring.AAO and DWF correlate well,with positive AAO tending to decrease DWF in North China.Two possible mechanisms for the AAO-DWF coupling are identified: one is related to a meridional teleconnection pattern;the other is related to a regional circulation pattern over the Pacific Ocean.The positive AAO anomaly decreases the cold activity over East Asia during boreal winter and spring.AAO-related barotropic meridional teleconnection from Antarctic to Arctic is found through analysis of mean meridional circulations.This meridional teleconnection is remarkable over Eurasia area during boreal winter and over the Pacific Ocean during boreal spring.Based on analysis of the long-term central North China precipitation(CNCP) time series reconstructed from the Qing Dynasty official document,it is found that the AAO is negatively correlated with the CNCP during JuneJuly.It follows that AAO-related variability of convergence and convection over the tropical western Pacific can exert impact on the circulation condition and precipitation in north China(actually,the precipitation in the Yangtze River valley as well) through atmospheric teleconnection known as the East Asia-Pacific(or Pacific Japan) teleconnection wave pattern.Researches show that the interannual of Mascarene high(MH) and Australian high(AH) in boreal spring may provide some useful information for the East Asian summer monsoon precipitation.With the intensification of MH during boreal spring through summer,the Meiyu rain tends to increase while the effect of AH on summer rain is confined to southern Ch