关于夏季南亚高压的进一步研究Ⅰ.与我国西北地区降水关系的统计分析

THE FURTHER STUDY ABOUT SOUTH ASIA HIGH IN SUMMER Ⅰ. STATISTIC ANALYSES OF RELATIONSHIP BETWEEN IT AND PRECIPITATION DISTRIBUTION OVER NORTHWEST CHINA

为了进一步统一分析夏季１００ｈＰａ南亚高压脊线和中心位置与西北地区降水的关系，利用１９７０～１９８５年７～８月逐日历史天气图及降雨量等资料，统计了南亚高压脊线和中心活动的基本特征；划分了逐日东、西部型及带状型南亚高压及持续的东、西部型南亚高压过程，还区分了西北区东、西部的多雨、少雨日。结果表明：南亚高压脊线和中心位置（特别是持续的东、西部型南亚高压过程）与西北区东。

In order to analyse the relationship between the 100 hPa Southern Asia High(SAH) and the precipitation over Northwest China in Summer, in this paper, firstly, the basic activity characteristics of the SAH and the relationship between the SAH and the precipitation over Northwest China are analysed, utilizing daily historical synoptic map data and precipitation map data of July and August during the period of from 1970 to 1985. The results show: (1) the 100 hPa SAH in summer stays mainly over Qinghai-Xizang Plateau and its neighbourhood, it suggests the impacts of the Plateau on the SAH. (2) When the monthly mean SAH ridge line is located somewhat south, the precipitation over the Northwest China will increase. (3) During the continuous processes of eastern pattern of the SAH, it will be rainy in the eastern part of Northwest China, but the dry weather in the western part of the Northwest China. During the continuous processes of western pattern of the SAH, the whole region of the Northwest China has little rain. (4) We sum also up the distribution of rainy area of eastern pattern of the SAH.