天津市城区静风与污染物浓度变化规律的分析

利用2000—2004年天津市城区气象和污染物资料,采用统计分析方法,研究了城区静风分布及污染物浓度变化规律。结果表明:静风分布有明显的日、年变化规律,在华北地形槽或低压、高压前部和高压的天气形势下易出现静风天气现象且持续时间较长。污染物浓度与风速呈现出较好的负相关,即风速越大、污染物浓度越小。但风速达到一定临界值时,TSP与风速呈正相关,大风可以引起二次扬尘并增加了空气中颗粒物的含量;PM10,SO2和NO2三种污染物在静风日的浓度值均高于非静风时的浓度值。

Analysis of calm wind and its relationship with pollutant concentration in Tianjin

Based on the meteorological data and the pollution data from 2000 to 2004 in Tianjin,the calm wind distribution and the pollutant concentration change were analyzed with statistical analysis method in the city zone of Tianjin.The results indicated that the daily and the yearly changes of calm wind distribution were obvious.Under the weather situation of topographic trough in north China or low pressure,the foreside of high pressure and high pressure,the calm weather occurred easily and its duration was longer.There was a negative correlation between the pollutant concentration and wind speed.That is to say,the larger the wind speed was,the lower the pollutant concentration was.However,when the wind speed reached a certain critical value,the relationship between total suspended particles(TSP) and wind speed was a positive correlation.The stronger wind could result in the second blowing dust and increase the grain contents in the air.The concentrations of PM10,SO2 and NO2 in calm weather were higher than that in non-calm weather.