北京市大气能见度规律及下降原因

The Study of the Status and Degradation of Visibility in Beijing

利用历史资料和外场观测数据,对北京市大气能见度的规律进行了分析。结果发现,北京市大气能见度较差的时间占全年的近一半。夏季能见度最好,冬季最差。通常中午能见度最好。高浓度的颗粒物是北京市大气能见度下降的主要原因。局地重污染天气和沙尘暴天气虽然发生几率小,但可以使北京市大气能见度下降得很低。

The visibility rules in Beijing were analyzed on the basis of historic data and field observational data.It was found that the visibility is some low in Beijing among almost half of the year.The summer is the best season for the visual range in Beijing,while the winter is the worst one.The highest vistibility was found usually around the noon.The high\|concentration particulates are the main reason to the visibility degradation.Although the possibility of sand storm and local severe polluted events is quite low in Beijing,it could lead a very low visual range.