中高纬大气环流异常和低纬30～60天低频对流活动对南海夏季风爆发的影响  

The Influences of Anomalous Atmospheric Circulation over Mid-High Latitudes and the Activities of 30-60 d Low Frequency Convection over Low Latitudes on the Onset of the South China Sea Summer Monsoon

作　　者：温之平[1] 黄荣辉[2] 贺海晏[1] 蓝光东[1] 

机构地区：[1]中山大学季风与环境研究中心/大气科学系,广州510275 [2]中国科学院大气物理研究所,北京100081

出　　处：《大气科学》2006年第5期952-964,共13页Chinese Journal of Atmospheric Sciences

基　　金：国家自然科学基金资助项目40275026;40505015

摘　　要：利用1979—2003年NCAR／NCEP-2再分析全球日平均资料，及1979-2003年全球候平均的CMAP降水和NOAA日平均的向外长波辐射资料，分析了中高纬大气环流异常和低纬30-60天低频对流的活动对南海夏季风爆发迟早的影响。分析结果表明，当5月1～15日期间乌拉尔山及其以西地区对流层出现位势高度负距平（低频气旋）、中纬度大陆为位势高度正距平（低频反气旋）、我国东部沿岸地区为位势高度负距平（低频气旋）、鄂霍次克海地区为位势高度正距平（低频反气旋）时，副热带高压脊较早撤出南海，与此同时，孟加拉湾东部低频对流活跃东传，菲律宾南部周围低频对流发展西移，华南地区低频对流活动南移以及加里曼丹低频对流活跃北移。在这种情况下，南海夏季风爆发偏早。相反，当5月1～15日期间乌拉尔山及其以西地区对流层出现位势高度正距平（低频反气旋）、中纬度大陆为位势高度负距平（低频气旋）、我国东部沿岸地区为位势高度正距平（低频反气旋）、鄂霍次克海地区为位势高度负距平（低频气旋）时，副热带高压脊撤出南海较迟；与此同时，孟加拉湾东部低频对流不活跃、东传晚，菲律宾南部周围低频对流不活跃、其西移与孟加拉湾东部低频对流的东传反位相，华南地区低频对流活动也不活跃，加里曼丹低频对流较弱。在这种情况下，南海夏季风爆发偏迟。The influences on the onset of South China Sea summer monsoon （SCSSM） of anomalous atmospheric circulation over mid high latitude areas and ＂the activities of 30 - 60 d low frequency convection over low latitude areas are studied by using the NCEP/NCAR 2 reanalysis data, CMAP （NOAA NCEP Climate Prediction Center Merged Analysis of Precipitation） precipitation data and NOAA OLR （outgoing longwave radiation） data. The results show that when there exists a anomalous wave train with negative anomalies of geopotential height field （low frequency cyclone） over the Ural Mountains and its western region and along the seacoast of eastern Asia, the positive anomaly （anomalous anticyclone） over middle latitude continent and the Sea of Okhotsk during May 1 - 15, the ridge of subtropical high will withdraws from the South China Sea （SCS） earlier. At the same time, low-frequency convection （LFC） over the eastern part of the Bay of Bengal is active and moves eastward, that around the Philippines develops and moves westward, that over South China is active and moves southward and that over Kalimantan is also active and moves northward. In this case, the establishment of SCSSM is earlier. On the other hand, when there exists a anomalous wave train with positive anomalies of geopotential height field （low frequency anticyclone） over the Ural Mountains and its western region and along the seacoast of eastern Asia, the negative anomaly （anomalous cyclone） over middle latitude continent and the Sea of Okhotsk during the first half month of May, the ridge of subtropical high will withdraws from the South China Sea （SCS） later. At the same time, the low-frequency convection （LFC） over the eastern part of the Bay of Bengal is not active and moves eastward later, that around the Philippines is also not active and its westward movement is opposite in phase with the eastward movement of the LFC over the eastern part of the Bay of Bengal, that over South China is not active and the intensity of

关 键 词：环流异常 30-60天振荡 低频对流 夏季风 爆发迟早 

分 类 号：P461[天文地球—大气科学及气象学]