2017~2020年冬季丹江口市城区气象条件对空气污染的影响

Impact of Meteorological Conditions on Air Pollution in Urban Areas of Danjiangkou City in Winter 2017~2020

摘要: 利用2017年~2020年冬季丹江口市城区的降水量、气温、风速风向、最小相对湿度、平均气压等气象要素与环境监测站空气质量数据进行对比分析，结果表明：① 2017年~2020年冬季，PM_2.5和PM₁₀为丹江口市城区大气污染的首要污染物，2018年和2017年污染日数较多。降水量越少，降水日数越少，无降水持续日数越长，日平均风速越小，东风日多于西风日，污染物堆积不易清除，使AQI指数升高。② 风速越大，越有利于两种污染物质量浓度降低；最小相对湿度越小，越有利于C(PM_2.5)的降低；日平均气温越高或降水量越大，越有利于C(PM₁₀)的降低。③ 连续性降水对污染物的清除作用优于单日降水，小于1 mm的单日降水对两种污染物无明显清除作用。C(PM_2.5)变化和C(PM₁₀)变化均与日最小相对湿度的变化最为密切，呈正相关；C(PM_2.5)变化与日平均风速变化呈反相关特征明显；C(PM₁₀)变化与日平均气温变化呈反相关特征明显。④ 东风日中，两种污染物质量浓度均高于西风日，C(PM₁₀)东风日与西风日的差值最大。C(PM_2.5)和C(PM₁₀)大值区多出现在锋面附近的南风中和东北路冷空气的偏东风中。

Abstract: Using the meteorological elements such as precipitation, air temperature, wind speed and direction, minimum relative humidity, average barometric pressure and other meteorological elements in the urban area of Danjiangkou City in the winter of 2017~2020 to compare and analyze with the air quality data of the environmental monitoring station, the results show that: ① PM_2.5 and PM10 are the primary pollutants of air pollution in the urban area of Danjiangkou City in the winter of 2017~2020, and the pollution in 2018 and 2017 the number of days is higher. The lower the pre-cipitation, the lower the number of precipitation days, the longer the number of days with no precipitation duration, the lower the average daily wind speed, the more easterly days than westerly days, the pollutants are not easy to be removed by the accumulation of pollutants, which makes the AQI index higher. ② The higher the wind speed, the more favorable the reduction of two pollutant mass concentrations; the smaller the minimum relative humidity, the more favorable the reduction of C(PM_2.5); the higher the daily average temperature or the larger the precipitation, the more favorable the reduction of C(PM₁₀). ③ Continuous precipitation is better than single-day precipitation in removing pollutants, and single-day precipitation less than 1 mm has no obvious removing effect on two pollutants. Changes in C(PM_2.5) and C(PM₁₀) are both most closely related to changes in daily minimum relative humidity, which is positively correlated; changes in C(PM_2.5) are inversely corre-lated with changes in daily mean wind speed, which is obvious; and changes in C(PM₁₀) are inversely correlated with changes in daily average air temperature, which is obvious. (PM₁₀) and daily mean air temperature are inversely correlated. ④ In the east wind day, the mass concentration of both pollutants is higher than that in the west wind day, and the difference between the east wind day and the west wind day is the largest for C(PM₁₀). The areas with large values of C(PM_2.5) and C(PM₁₀) are mostly found in the southerly winds near the frontal surface and in the easterly winds from the northeast road cold air.