1963—2002年南通地区旱涝天气气候事件的类型及其预兆

Type of Climate Events of Meteorological Drought and Weathersign of Nantong Area in 1963—2002

针对南通地区1963—2002年所发生的气象旱涝天气气候事件,利用同期该地区8个站地面气象观测资料,计算降水量距平百分率,按国家标准气象干旱等级的划分其等级,用8:00(北京时间)500 hPa历史天气图资料,以天气学原理为基础,分析旱涝事件的特征及其成因,划分天气类型,探明其引发的主要因子。结果表明,南通地区的气象旱涝天气气候事件与降水量异常欠亏和丰沛紧密相连。引发旱涝的主要天气系统是:西太平洋副热带高压西伸脊、大陆暖高(指云贵高压和南海高压),南支西风槽和台风。干旱发生在副热带高压西伸脊内的下沉绝热增温的辐散区和西风槽后,洪涝产生在南支西风槽前锋际的连阴雨区、强降水区和台风的暴雨区。厄尔尼诺现象和拉尼娜事件与南通地区的旱涝气候事件间有一定的相关。南通地区上年12月至当年3月的月尺度气温距平百分率与6—8月的旱涝气候事件分别有150 d和180 d的韵律对应。

Aimed at the climate events of meteorological drought of Nantong Area in 1963--2002,using the ground meteorological observation data of 8 stations in the corresponding period ,the percentage of precipitation anomaly was calculated.According to the classification of meteorological drought category of China,grade was divided.Using the 500 hPa historical weather map information of 08 am （Beijing Time）,based on the synoptic meteorology principles ,the characteristics and causes of drought and flood events was analyzed and weather types were divided, the main factors of its cause was proved.The results showed that meteorological drought weather events was closely linked with rainfall anomaly losses and abundant.Riggering droughts and major weather systems were the West Pacific subtropical high ridge west ,the mainland warm high （refer to Yunnan ,Guizhou ,South China Sea ,high pressure and high pressure）and the South Branch of the westerly trough and typhoons.Drought occurred in the subtropical ridge westward extension of the adiabatic warming in the sink area and the westerly trough divergence ,the floods had westerly trough in the southern branch of the continuous rain inter striker area ,heavy rainfall and typhoon storm area.E1 Nino and La Nina drought and flood events and climate events of Nantang area had a certain correlation.temperature departure percentage under monthly scale between December in the last year to March in the same year had 150,180 days corresponding rhythm with drought weather events from June to August.