大气污染物干沉降速度和通量的计算方法比较——以南京仙林地区为例  

Comparison of Methods for Dry Deposition Velocity and Flux Estimation of Atmospheric Pollutants——A Case Study in Xianlin District, Nanjing

作　　者：赵雄飞 王体健[1] 黄满堂 杨帆 杨丹丹 金龙山[1] ZHAO Xiong-fei;WANG Ti-jian;HUANG Man-tang;YANG-Fan;YANG Dan-dan;JIN Long-shan(School of Atmospheric Sciences,Nanjing University,Nanjing 210023,China)

机构地区：[1]南京大学大气科学学院

出　　处：《装备环境工程》2019年第6期129-137,共9页Equipment Environmental Engineering

基　　金：国家重大科技研发项目(2017YFC0210106,2016YFC0203303);国家自然科学基金项目(41575145,91544230)

摘　　要：目的基于不同方法对大气污染物干沉降速度和通量的估计存在差异,开展比较研究。方法2016年9月至2017年9月,在南京大学仙林校区,基于75m观测塔,对大气中常见的六种污染物二氧化硫(SO2)、一氧化氮(CO)、二氧化氮(NO2)、臭氧(O3)、一氧化碳(CO)、细颗粒物(PM2.5)的浓度和气象要素进行连续观测。利用三层阻力模型计算大气污染物的干沉降速度,利用浓度法和梯度法计算干沉降通量,并对两种方法进行比较。结果SO2、NO、NO2、O3、CO、PM2.5的平均干沉降速度分别是0.270、0.019、0.089、0.449、0.038、0.147cm/s。干沉降速度具有明显的日变化特征,一般情况下,白天大于夜间,在午后出现最大值。整个观测期间,采用浓度法计算得到的SO2、NO、NO2、O3、CO、PM2.5干沉降通量分别为0.034、0.008、0.037、0.263、0.354、0.049μg/(m^2·s),采用梯度法得到的干沉降通量分别为0.04、0.00193、0.035、0.278、0.192、0.063μg/(m^2·s)。结论对于NO、O3、PM2.5,浓度法和梯度法计算的干沉降通量具有较好的一致性。梯度法估计干沉降通量时很大程度上依赖于大气污染物浓度梯度测量的准确性,浓度法估计干沉降通量则更多依赖于干沉降速度计算的准确性。Objective To compare the difference of dry deposition velocity and flux of atmospheric pollutants estimated with different methods.Methods Based on the 75 m observation tower,six pollutants concentration in the atmosphere,such as sulfur dioxide(SO2),nitrogen monoxide(NO),nitrogen dioxide(NO2),ozone(O3),carbon monoxide(CO),and fine particulate matter(PM2.5)and meteorological elements were observed at the Xianlin Campus of Nanjing University during 13 months(September 2016 to September 2017).The dry deposition velocities of atmospheric pollutants were calculated by the three-layer resistance model and the dry deposition fluxes ware calculated by the inferential method and the gradient method;and then the two methods were compared.Results The average dry deposition velocities of SO2,NO,NO2,O3,CO and PM2.5 were 0.270,0.019,0.089,0.449,0.038 and 0.147 cm/s respectively.The dry deposition velocity had obvious daily variation characteristics.Gener ally,the variation in the daytime was greater than that in the nighttime,and the maximum value appeared in the afternoon.During the whole observation period,the dry deposition fluxes of SO2,NO,NO2,O3,CO and PM2.5 calculated by the inferential method were 0.034 0.008,0.037,0.263,0.354,0.049μg/(m^2·s)respectively,and the dry deposition fluxes obtained by the gradient method were 0.04,0.00193,0.035,0.278,0.192,63μg/(m2·s)respectively.Conclusions For NO,O3,PM2.5,the dry deposition flux calculated by inferential method and gradient method has good consistency.Estimation of the dry deposition flux by the gradient method largely depends on the accuracy of the concentration gradient measurement.Estimation of the dry deposition by the concentration method more depends on the calculation accuracy of the dry deposition rate.

关 键 词：干沉降通量 干沉降速度 浓度法 梯度法 

分 类 号：X511[环境科学与工程—环境工程]