冬季西太平洋副热带高压脊线位置异常与热带对流异常的关系  

The Relationship between the Ridge Line Position of the Western Pacific Subtropical High and the Tropical Convection Anomaly in January

作　　者：高睿[1] 郭换换[2] 郭胜利[1] 

机构地区：[1]南京信息工程大学环境科学与工程学院,南京210044 [2]南京信息工程大学大气科学学院,南京210044

出　　处：《科学技术与工程》2015年第6期120-126,共7页Science Technology and Engineering

基　　金：国家重大科学研究计划"973"项目(2012CB955200)资助

摘　　要：利用NCEP/NCAR再分析资料、射出长波辐射（OLR）资料,国家气候中心提供的1979-2008年1月西太副高脊线指数和逐日降水资料,对1月西太副高脊线位置与热带对流异常的关系进行了分析。结果表明,1月西太副高脊线位置与南海及菲律宾以东地区OLR场存在显著的负相关关系。进一步研究发现,副高脊线的南北位置异常是由于南海及菲律宾以东地区对流偏强（弱）造成这一区域出现异常的上升（下沉）运动;由于对流层高层（低层）南风距平的作用,在我国东南部的下沉运动增强（减弱）;同时,在对流层的低（高）层出现了异常北风,从而构成了一个向北（南）的经向环流,有利于副高脊线的北抬（南退）。这种对流异常是造成2008年初我国南方超过1/3区域出现了50年一遇的低温、雨雪、冰冻灾害的间接原因之一。Based on the NCEP/NCAR reanalysis data,OLR（ Outgoing Long-wave Radiation） data,the ridge line index of the Western Pacific Subtropical high（ WPSH） and daily precipitation data supported by National Climate Center from 1979 to 2008,the relationship between the ridge line position of the WPSH and the tropical convection anomaly in January has been investigated. The results show that the ridge line position of the WPSH is negatively correlated with the OLR fields in the east of the Philippines and the South China Sea（ SCS）. The reason of the abnormal ridge line position is that the stronger（ weaker） convection makes the anomalous rising（ sinking） motion occur above the east of the Philippines and the SCS. In addition,due to the anomalous southerly in upper（ low） troposphere,the abnormal sinking motion in the southeastern China has been strengthened（ weakened）. At the same time,the abnormal northerly occurs in low（ upper） troposphere. As a result,a meridional circulation which has the same（ anti） phase with the Hadley circulation has been formatted,and the ridge line position of the WPSH stretches toward the north（ south）. And more than a third of stations in southern China were covered by the extreme weather event as low temperature,snow and freezing disaster that appears once in a 50-yearin early 2008.The strong convection over the east of the Philippines and the SCS may play an indirect role in the formation of these extreme events.

关 键 词：冬季西太副高脊线 热带对流 经向环流 冰冻灾害 

分 类 号：P424.41[天文地球—大气科学及气象学]