摘要
对北京市2003—2009年的全市性酸雨过程进行研究,分析了影响北京地区酸雨的主要天气系统,并结合气流后向轨迹分析和上甸子站酸雨离子成分浓度分析,得到如下结论:影响北京地区酸雨的天气系统主要为低涡低槽型、西来槽型和副高边缘型天气系统。3种天气系统对应的降水平均pH值均小于4.5,达到强酸雨水平。降水前北京地区受持续的偏南风影响、上升运动的强度较强且维持时间较长,降水前出现逆温现象,都是导致北京地区出现强酸雨的重要因素。对北京大气污染有影响的气流轨迹在低涡低槽、西来槽和副高边缘型天气系统的比例分别为59%、74%和66%。西来槽型天气系统的电导率K值与水溶性离子浓度明显高于低涡低槽型和副高边缘型。
Through citywide acid rain events during 2003—2009 in Beijing area,we analyzed the synoptic backgrounds of acid rain,backward trajectory and the chemical composition of Shangdianzi station,the conclusions are as follows： low vortex and low trough,westerly trough and the border of WPSH（western Pacific subtropical high） are the major synoptic systems during acid rain events.The pH value of Beijing area under the above-mentioned 3 synoptic backgrounds are all below 4.5.Precipitation process of the westerly trough synoptic system has great influence on acid rain in Beijing area.The major factors of causing acid rain includes： durative south wind,temperature inversion before precipitation,strong and persistent ascending motion.The proportions of pollution due to airflow trajectory of low vortex and low trough,westerly trough and the border of WPSH are 59%,74% and 66% respectively.Value of conductivity and concentration of water-soluble ions in westerly trough synoptic system is higher than that of in low vortex and low trough and the border of WPSH synoptic system.
出处
《气象科学》
CSCD
北大核心
2012年第5期565-572,共8页
Journal of the Meteorological Sciences
基金
北京市气象局气象科技研发专项(2012BMBKYZX08)
北京市自然科学基金(8092010)
关键词
酸雨
天气系统
后向轨迹
PH值
离子浓度
Acid rain
Synoptic background
pH value
Backward trajectory
Chemical compositions
