The leading correlation of the winter Aleutian Low with surface air temperature during the subsequent summer over the Arctic and its possible mechanism  

作　　者：Fuan Xiao Hua Jiang Bingyi Wu Hui Wang Xiang Li 

机构地区：[1]Chinese Academy of Meteorological Sciences [2]National Marine Environmental Forecasting Center [3]National Marine Data and Information Service

出　　处：《Chinese Science Bulletin》2014年第9期904-912,共9页

基　　金：supported by the National Natural Science Foundation of China(40976014,41076011,41106024 and 41106159)

摘　　要：The variations of surface air temperature(SAT)over the Arctic are closely related to global climate change.Based on reanalysis datasets and a newly defined Aleutian Low intensity index,we found a good correlation between intensity of winter Aleutian Low and the SAT over the Arctic during the subsequent summer.Explanations were given using correlation analysis,composite analysis,and singular value decomposition methods.When intensity of winter Aleutian Low was weaker,sea surface temperature appeared higher in the North Pacific in the subsequent spring and summer,resulting in mean meridional circulation anomalies and 500 hPa geopotential height anomalies in spring and summer.Anomalous upward motion in mid-latitudes and downward motion in high latitudes(Ferrel cell weakening)transported the warmer air to the north from lower layer to the upper layer followed by increases in the SAT over the Arctic.Anomalous downward motion over about 75°N also caused consequent adiabatic warming and contributed to inhibit the heat transportation from surface to upper layer.Negative 500 hPa geopotential height anomalies existed in mid-latitudes and positive anomalies existed in high latitudes.The pattern(low-in-south and high-in-north)benefited from increasing the inflow volume flux of the Bering Strait,which also made the SAT over the Arctic increase.The results of this study reveal the process that the summer SAT over the Arctic was modulated by interannual variability of intensity of winter Aleutian Low.The variations of surface air temperature （SAT） over the Arctic are closely related to global climate change. Based on reanalysis datasets and a newly defined Aleutian Low intensity index, we found a good correlation between intensity of winter Aleutian Low and the SAT over the Arctic during the subsequent summer. Explanations were given using correlation analysis, composite analysis, and singular value decomposition methods. When intensity of winter Aleutian Low was weaker, sea surface temperature appeared higher in the North Pacific in the subsequent spring and summer, resulting in mean meridi- onal circulation anomalies and anomalies in spring and summer 500 hPa geopotential height Anomalous upward motion in mid-latitudes and downward motion in high latitudes （Ferrel cell weakening） transported the wanner air to the north from lower layer to the upper layer followed by increases in the SAT over the Arctic. Anomalous downward motion over about 75°N also caused consequent adiabatic warming and contributed to inhibit the heat transportation from surface to upper layer. Negative 500 hPa geopotential height anomalies existed in mid-latitudes and positive anomalies existed in high latitudes. The pattern （low-in-south and high-in-north） benefited from increasing the inflow volume flux of the Bering Strait, which also made the SAT over the Arctic increase. The results of thisstudy reveal the process that the summer SAT over the Arctic was modulated by interannual variability of intensity of winter Aleutian Low.

关 键 词：阿留申低压 北极地区 夏季 冬季 地面气温 国家税务总局 海洋表面温度 奇异值分解方法 

分 类 号：P463.1[天文地球—大气科学及气象学]