沈阳近地层大气颗粒物浓度垂直变化特征及与气象因子的关系

利用2018年10月1日至2019年9月30日沈阳地区三个高度大气颗粒物浓度和气象要素逐时观测资料，分析了不同高度颗粒物浓度时间变化特征及其与气象要素的关系。结果表明：不同高度的颗粒物浓度均存在明显的季节变化，秋冬季数值明显高于春夏季。冬季，三个高度的PM_2.5平均浓度为54.98±12.67 μg·m^-3、63.77±15.1 μg·m^-3和39.27±5.62 μg·m^-3，即15 m > 1.5 m > 90 m，秋季对应高度的浓度值则为1.5 m > 15 m > 90 m，春季对应高度的浓度值1.5 m≈15 m>90 m，夏季对应高度的浓度值15 m > 90 m > 1.5 m。PM_2.5、PM₁₀和TSP浓度的日变化在秋冬季三个高度上均呈明显的双峰，春季则均为单峰，夏季15 m高度为单峰，其余两层无明显规律。月平均颗粒物浓度的变化在冬、夏半年之间存在明显差异。冬半年，1.5 m高度PM_2.5、PM₁₀和TSP以及90 m高度PM_2.5月平均浓度均表现为增—减—增—减的变化特征，而15 m高度月平均PM_2.5、PM₁₀和TSP浓度以及90 m高度月平均PM₁₀、TSP浓度均为先增后减的变化特征。冬半年和夏半年颗粒物浓度最大值分别出现在1月和6月，冬半年最低两层高度的颗粒物浓度明显高于90 m的值，夏半年各月不同高度颗粒物浓度相差不大，均远低于冬半年的浓度值。不同粒径范围的颗粒物浓度与风速和气温均呈负相关关系，且相关系数随高度增加而增加，随颗粒物粒径范围增加而变小；与相对湿度的关系较为复杂，相关系数随观测高度增加和颗粒物粒径范围的增大而有所不同。

Vertical distribution of atmospheric particulate concentration over the surfacelayer and its relationship with meteorological factors in Shenyang

Based on the observed PM_2.5,PM₁₀,TSP concentrations and meteorological factors including wind speed,air temperature,relative humidity at 1.5 m,15 m,and 90 m heights from October 1,2018,to September 30,2019,in Shenyang,the vertical variation characteristics of atmospheric particulate concentration(APC)at different heights and their relationships with meteorological factors were analyzed.The results indicated that concentrations of different atmospheric particulates experience seasonal variations at different heights.The autumn and winter APCs are higher than those in spring and summer.The values of winter PM_2.5 concentration at 1.5 m,15 m,and 90 m heights are in turn 54.98±12.67μg·m^-3,63.77±15.1μg·m^-3,39.27±5.62μg·m^-3,i.e.,the value at 15 m is greater than those at 1.5 m and 90 m,the corresponding values in autumn,spring and summer are in order of 1.5 m,15 m,90 m,the value at 1.5 m≈that at 15 m while the value at 15 m>that at 90 m,i.e.value(15 m)>value(90 m)>value(1.5 m),respectively.The diurnal variations of PM_2.5,PM₁₀,TSP concentrations are in the significant bimodal patterns in autumn and winter and unimodal patterns in spring at the three vertical heights,while the variations are in a unimodal pattern at 15 m height and have no obvious patterns at the other heights in summer.The variations of monthly mean APC show a significant difference between winter and summer seasons.Also,the concentrations of different sizes of atmospheric particulates vary with heights.In winter half-year,the monthly mean PM_2.5,PM₁₀,TSP concentrations at 1.5 m height and PM_2.5 concentration at 90 m height indicate the change characteristics of increase-decrease-increase-decrease,while the monthly mean PM_2.5,PM₁₀,TSP concentrations at 15 m height and PM₁₀,TSP concentrations at 90 m height tend to increase first and then decrease.The maximum values of APC in winter and summer half years occurred in January at 15 m height and June at three heights,respectively.The APCs at the two lower heights are higher than those at 90 m height in the winter half-year.In the summer half-year,the APCs among three heights have little difference and are much less than those in the winter half-year.The daily mean PM_2.5,PM₁₀,TSP concentrations are negatively correlated with wind speed and air temperature,and the correlation coefficients increase with the increase of the height and decrease with increase of the particle size.The relationships between daily mean PM_2.5,PM₁₀,TSP concentrations,and relative humidity are relatively complex,and the correlation coefficients vary with increase of the vertical height and particular size.