2015年呼和浩特市PM2.5、PM10污染特征及其与气象条件的关系

为了研究呼和浩特市污染特征及其与气象条件的关系，利用大气环境监测数据和常规气象观测资料，分析2015年PM_2.5、PM₁₀浓度特征及与气象要素的关系；结合11月末呼和浩特市严重雾霾天气，对其成因进行初步分析。结果表明：（1）呼和浩特市冬季PM_2.5与PM₁₀浓度是四季中最高，夏季最低；2015年月均最大值出现在12月，PM_2.5与PM₁₀浓度变化趋势基本一致，年平均相关系数为0.711；（2）PM_2.5浓度与能见度、气压、相对湿度的相关系数分别为：-0.887、0.815、0.501；与风向风速及降水量年均相关性不明显；（3）2015年呼和浩特市11月降水明显加强，而冷空气势力较弱，风速小，气温偏高，29日呼和浩特市上空形成了逆温层，维持时间较长，这正是雾霾持续出现及异常加强的一个重要原因，冬季采暖是11月污染物浓度加强的另一个重要原因。

Pollution Characteristics of PM2.5 and PM10 and Their Relationships with Meteorological Conditions in Hohhot, 2015

In this paper, pollution characteristics of PM_2.5 and PM₁₀ and their relationship with meteorological factors of Hohhot City in 2015 were analyzed using atmospheric environmental monitoring data and meteorological observation data in Hohhot City, and causes of thesevere fog and haze at the end of November in Hohhot City were analyzed preliminarily. The results showed that: (1)fine particulate matter pollution in HohhotCity was heavy, and the pollution of coarse particulate matter was relatively low.The concentrations ofPM_2.5 and PM₁₀ were highest in winter and lowest in summer, and the maximum monthly mean value of which in 2015 appeared in December.The trends of PM_2.5 and PM₁₀ concentration were basically the same in the whole year, andthe correlation coefficient of annual mean value was 0.711. (2)The correlation coefficient ofconcentrationof PM_2.5 and visibility,air pressure,relative humiditywere -0.887, 0.815,0.501,respectively. There is no significant correlation between concentration of PM_2.5and wind velocity and direction, precipitation, which may be related to the low annual mean wind velocity, notobviouschange of wind direction and precipitation phase. (3) One of the important reasons of persistent andabnormal strengthening of fog and haze of Hohhot City in November 2015 was related to the long time inversion layer over the Hohhot City, which was caused by increasing humidity (light to moderate drought in spring and summer and precipitation increased significantly in November),weak cold air force, low wind velocity and high temperature phenomenon. And winter heating is another important reason for the strengthening of pollutant concentration in November.