基于欧拉观测的大气扩散参数计算方法

利用超声风速仪对吉林省敦化市大石头镇进行了夏、冬季各10 d的观测。根据大气湍流扩散参数统计理论,利用欧拉观测的风速资料求解正态扩散模式中的大气扩散参数。结果表明:2005年夏季和2007年冬季B—F类稳定度的σy和σz均呈减小趋势,横轴y方向的总体扩散水平大于垂直方向z轴的总体扩散水平。夏季的σy在B—D类明显高于冬季的σy,且随着水平距离的增加更为明显;E—F类,夏季的σy在x=100 m处,略低于冬季,但随着水平距离的增加,夏季的σy比冬季的σy增加更快;夏季的σz在B—F类均高于冬季的σz,且随着水平距离的增加更为明显。该计算方法具有可操作性和实用性,可作为研究该地区大气湍流扩散规律和污染模式选取参数的依据。

Estimating atmospheric diffusion parameters based on Eulerian observation

Wind speed was observed in summer(from August 25 to September 13,2005) and in winter(March 20—29,2007) with ultrasonic anemometer in Dashitou town,Dunhua city,Jilin province.Based on the statistical theory of turbulent diffusion parameters,the atmosphere diffusion parameters of normal diffusion model were calculated by Eulerian observation.The results indicate that σy value and σz value under different atmospheric stabilities(B,C,D,E and F types) decrease in the summer of 2005 and in the winter of 2007.The total diffusion level of transverse y-axis is higher than that of vertical z-axis.σy values under B,C and D types in summer are higher than those in winter,which becomes obvious with the increase of horizontal distances.σy values in summer are less than those in winter when x equals 100 m.Compared with σy values in winter,σy values in summer increase rapidly with the increase of horizontal distance for E stability and F stability.σz values under B,C,D,E and F stabilities in summer are higher than those in winter,which become obvious with the increase of horizontal distances.This method is feasible and practical.And it can be used as a parameter selection reference of atmospheric turbulence diffusion rule and pollution model in this area.