鲁南夏季降水与南亚高压及大气环流的关系分析

摘要

[目的]研究鲁南夏季降水与南亚高压及大气环流的关系.[方法]以位于黄淮的鲁南地区降水为研究对象,利用1961～2005年NCEP/NCAR资料和鲁南夏季26个站降水资料,分析了鲁南夏季旱年和涝年南亚高压及大气环流的特点,探讨100 hPa南亚高压影响鲁南降水的机制,并分析了高低层大气环流的不同配置以及不同纬度、不同系统之间的相互作用.[结果]鲁南夏季降水EOF分解的第1模态解释了63％以上的方差,反应了降水的普遍形式.旱年和涝年南亚高压高度场中心位置偏差不大,但风场中心并不一致.当100hPa等压面亚洲90°E以东、贝湖以南地区为异常气旋式切变,中低层为异常气旋时,南亚高压面积偏小,其东部高压脊线经鲁南和长江口之间伸向西太平洋,鲁南夏季偏涝;当l00 hPa等压面亚洲90°E以东、贝湖以南地区为异常反气旋式切变,中低层为异常反气旋时,南亚高压面积偏大,其东部脊线经长江口附近伸向西太平洋,鲁南夏季偏旱.鲁南夏季降水与亚欧大陆上高纬的东西向遥相关波列和东亚-西太平洋经向的PJ型遥相关波列均存在密切的关系,当亚欧大陆高纬地区里海以北、贝湖附近、堪察加半岛地区高度距平呈“+- +”波列,东亚-西太平洋地区高度距平从低纬到高纬呈“- +”波列时,鲁南夏季偏涝；反之,鲁南夏季偏旱.[结论]该研究为鲁南夏季降水的机制分析提供理论依据.%[Objective]The relation among summer rainfall in south Shandong and high pressure in south Asia and atmospheric circulation. [ Method] Taking the precipitation in south Shandong along the Yellow River and Huaihe River, using the NCEP/NCAR data and summer rainfall data in South Shandong in summer from 1961 to 2005, the characteristics of high pressure in south Asia and atmospheric circulation in drought year and flood year in summer in south Shandong Province were expounded. The mechanism of 100 hPa pressure in south Asian influ encing precipitation in south Shandong Province was discussed. The interaction of different equipment, different altitude and different system of atmosphere circulation in low and high layer was expounded. [ Conclusion ] The first mode of EOF decompose of precipitation in summer in south Shandong Province explained above 63% variances and reflected universal form of precipitation. The difference of central position of the central position of height field of high pressure in south Asia in drought and flood year was small. But the wind field center was inconsistent. As the area of SAH was smaller and it' s eastern ridge line stretched to the western Pacific between the middle of South Shandong and Chang Jiang Estuary, flood summer was occurred when there was an unusual cyclone lied in the East of 90° E and South of Lake Baikal, the area of SAH was larger and it's eastern ridge line stretching to the western Pacific over Chang Jiang Estuary, drought summer occurred ,when there was an unusual anticyclone lied in the East of 90° E and South of Lake Baikal. SAH and summer rainfall also had close relationship with Tele connection Patterns over the Eurasia continent and EAP Teleconnection. When the height anomaly was in " + - + " form in the north of the Caspian Sea, around lake Baikal and Kamchatka, and when the height anomaly in East Asia-West Pacific area was in " - + " form from low altitude to high altitude, there was much precipitation in summer; and conversely, it was drought in summer in south Shandong.