铜陵市空气污染物浓度与大气混合层高度的关系

Dependence of Air Pollutants Concentration on Mixing Height in Tongling City

以长三角地区典型工业城市为研究对象,利用气象探空站观测数据,采用干绝热曲线法计算代表大气垂直方向上大气混合能力的最大混合层高度,并与地面观测的空气污染物浓度观测结果进行对比分析。分析结果表明,2-4月和7-10月是月均最大混合层高度较高的2个时期;在季节变化上呈现出春季到冬季依次下降的特征,东亚季风气候是造成这些特征的主要原因之一。总体而言,随着最大混合层高度的增大,各污染物的最大可能浓度呈现出不同的降低趋势。最大混合层高度对颗粒态污染物(PM_(10),PM_(2.5))日均浓度的影响最为显著,主要原因是颗粒态污染物相对稳定、且生命周期长。对于气态污染物而言,化学性质稳定的CO的最大日均浓度与最大混合层厚度之间关系最好,其次为SO_2和NO_2。O_3由于化学性质不稳定且受太阳辐射影响显著,其最大日均浓度与最大混合层高度之间关系相对较差,但也存在着-0.692的负相关。

Taking a typical industrial city of Yangtze River Delta region as a case study,the relationships between air pollution and atmospheric condition are focused with meteorological sounding data and air pollution content observation data.The maximum mixing height（MMH）has been estimated by the method of Holzworth dryadiabitic method.And then,the observation results of air pollutants concentrationon ground are analyzed with the MMH data.As the results shown,there are two high MMH periods during a year,one high period is spring from February to April,and another is summer and autumn from July to October.For the seasonally characters,the MMH is declined from spring to winter by the affected East Asia monsoon.The daily mean concentrations of particular pollutants（PM10,PM2.5）,which are with stabilities attributive and long life period,are influenced most significantly by MMH.As to the correlation with gaseous pollutants maximum daily average concentration（Cmax）and MMH,the CO is best for its chemical stability,and followed by SO2and NO2.Although the correlation of O3is worst due to its chemical instability and sensitivity of solar radiation,the correlative coefficient of Cmax and MMH has been reached -0.692.