城市空气湿度变化特征及其对颗粒物浓度的影响

CHARACTERISTICS OF URBAN AIR HUMIDITY AND ITS IMPACT ON PARTICLE

为研究城市空气湿度变化特征以及对颗粒物浓度的影响,选取以成都为例,利用相对湿度、绝对湿度及其颗粒物(PM_(10)、PM_(2.5))浓度值,分析了成都市空气湿度不同时间尺度变化特征及其对颗粒物的影响,结果表明:成都市平均相对湿度、绝对湿度分别为77.10%、11.40 g/m^3,其中相对湿度多集中在80%~95%,绝对湿度集中在4.5~10.5 g/m^3,近5年两类湿度参量均有逐年增加的趋势,但两者在年、季节、日变化特征差异较大,多项式拟合可以较好的模拟成都市湿度参量的变化特征;两类湿度参量对颗粒物浓度的影响表现不同,相对湿度越大时,空气越趋近饱和,颗粒物浓度偏高,而绝对湿度越大时,大气湿沉降作用强,颗粒物浓度偏低。

For studying the characteristics of urban air humidity and its impact on particle,taking the observation data from Chengdu as an example,the hourly data of relative humidity,absolute humidity and concentration of particulate matter（ PM10,PM（2. 5）） were studied,and the results showed that： The average of relative humidity,absolute humidity of Chengdu was77. 10%,11. 40 g/m^3,respectively. The distribution of relative humidity was concentrated at 80% ～ 95%,while the distribution of absolute humidity was concentrated at 4. 5 ～ 10. 5 g/m^3. Although,those two humidity parameters tended to increase,the annual,seasonal,daily variation characteristics were quite different,and the variations were fitted well by cubic curve-fitting equation. The effects of two humidity parameters on particle concentration were different; the greater the relative humidity was,the more saturate the air tended,and particle concentration was higher; when absolute humidity was higher,the atmospheric wet deposition got stronger,and particle concentration was lower.