作　　者： (陈磊）; (俞科爱）; (林宏伟）; (孙军波）; (蒋飞燕）; (孙仕强）;

机构地区： 慈溪市气象局,浙江慈溪315300

出　　处： 《气象与环境学报》 2017年第4期40-47,共8页

摘　　要： 基于2001—2014年宁波市每日4个时次(02时、08时、14时、20时)的常规气象观测资料和同期宁波市环保局空气污染物(SO_2、NO_2、PM_(10))浓度的日监测数据,采用最小二乘曲线拟合法计算了2001—2014年宁波市大气混合层厚度,并分析了大气混合层厚度的时间变化特征及其与空气污染的关系。结果表明:2001—2014年宁波市年平均大气混合层厚度波动变化明显,大气混合层厚度极大值和极小值分别出现在2004年、2007年,分别为866.1 m和746.1 m。水平风速对宁波市大气混合层厚度的影响较大。春季和7月、8月宁波市大气混合层厚度较大,秋季和冬季大气混合层厚度较小,而6月大气混合层厚度最小。大气混合层厚度在中午达最大值,夜间达最小值,大气混合层位于500.0—1200.0 m高度的出现频率最高。随着大气混合层厚度增大,污染物浓度被稀释。夏季,大气混合层厚度对PM_(10)、SO_2和NO_2浓度的调节能力较强。由于输入性污染的影响,冬季PM_(10)与SO_2浓度的极大值明显高于夏季,同时大气混合层厚度的变化对PM_(10)和SO_2浓度的增减效应比夏季明显削弱,但对NO_2浓度的影响较小。另外,当大气混合层厚度位于500.0—1200.0 m高度时,在同一大气混合层厚度下,同一污染物浓度的变化范围较大。 Based on the 6-hourly conventional meteorological observation data and the daily air pollutant concentra-tion data from Ningbo Environment Protection Bureau,the least square method was used to calculate atmospheric mixed layer thicknesses and analyze their temporal variations,along with their relationships with air pollution dur-ing 2001 to 2014. The results show that the annual average atmospheric mixed layer thicknesses vary obviously, and the maximum and minimum appear in 2004 and 2007,with the values of 866. 1 m and 746. 1 m,respectively. Horizontal wind speeds are key factors to atmospheric mixed layer thicknesses over Ningbo. The thicknesses are relatively larger during July and August, whereas smaller during autumn and winter, the minimum appearing in June. As for the diurnal variations,the maximum appears in the noon,whereas the minimum appears at night. The highest frequency of atmospheric mixed layer thicknesses occurs at the levels between 500 m and 1200 m. The pol-lutants are diluted with increasing the thickness of the mixed layer. In summer,the atmospheric mixed layer thick-nesses significantly modulate the concentrations of PM10 ,SO2 ,and NO2 . But in winter,due to the pollutant trans-port,the maximum concentrations of PM10 and SO2 are much higher,while the dilution effect of atmospheric mixed layer thicknesses is much weaker than in summer. There is little influence on NO2 concentrations. In addition,when atmospheric mixed layer thicknesses reach to the levels of 500-1200 m,the range of concentration for the same pol-lutant is relatively larger for the same mixed layer thickness.

关 键 词： 大气混合层厚度 最小二乘曲线拟合 空气污染 相关分析