摘要:
利用重庆地区23个气象站1960-2007年逐日最高气温观测资料和同期NCEP/NCAR再分析资料探讨重庆夏季高温天气的气候特征,选取2006年和三个有代表性的高温天气过程进行环流场特征分析.结果表明:重庆地区的夏季高温事件具有显著的年代际变化和区域差异,20世纪80年代发生频次最少,70年代最多,沿长江、乌江为高温天气多发带;南亚高压位置偏东,西太平洋副热带高压偏西,南亚高压与西太平洋副高的上下叠加是重庆地区夏季高温天气过程的主要环流特征.分析认为,100 hPa等压面上的南亚高压、300 hPa等压面上的暖中心和500 hPa等压面上的副热带高压脊控制着四川东部及重庆地区上空,对流层中上下层暖高压中心相对应、中心位置基本一致是出现大范围、持续性异常高温天气的重要原因.
Abstract:
The climatological features of summer high temperature in Chongqing are discussed based on the data of day-to-day maximum temperature during 1960-2007 recorded by 23 meteorological stations in Chongqing area and the NCEP/NCAR re-analysis data for the same period,and the circulation situations of 3 extreme high temperature cases in Chongqing climate history are analyzed.The results show that the high temperature days and the high temperature events have obvious inter-decadal and regional distinctions,with the lowest frequency in the 1980s and the highest in the 1970 s.The regions along the Yangtze River and the Wujiang River are the locations with frequent high temperature weather in Chongqing.The main circulation characteristic of the high temperature weather may be the eastward movement of the South Asia high and the westward movement of the West Pacific subtropical high,which results in the up-anddown high pressure superposition in the atmospheric stratosphere.High temperature weather occurs widely and continuously when East Sichuan and Chongqing are dominated by South Asia high on the 100 hPa isopressure surface,warm center On 300 hPa isopressure surface and subtropical high on 500 hPa isopressure surface with consistent warm high center location on up tropsphere and underlayer.
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