基于AERMOD模式的大气扩散参数方案比较研究

在美国法规空气质量模式AERMOD的框架下,比较了4种已被广泛应用的扩散参数化方案(基于边界层微气象要素的AERMOD湍流参数化方案,基于湍流观测资料和扩散函数的Tub-Obs方案,Briggs参数化方案,NEPA方案).分析了不同稳定度、不同扩散参数方案下的污染物SO2地表浓度差别.总体来说,在中性和不稳定条件下,4种方案模拟结果的差别不大;在稳定条件下, AERMOD方案的地面浓度明显低于Briggs和NEPA方案,可能是由于AERMOD方案不能很好地识别局地湍流的贡献.

Comparison of different schemes for diffusion parameterization based on AERMOD

Based on framework of the US EPA regulatory air quality model (AERMOD), comparisons were conducted for four widely-used diffusion parameterization schemes, one based on micro-meteorological elements (AERMOD scheme), one based on turbulence observation (Tub-Obs scheme), one based on the Briggs' formulae (Briggs scheme), and one adopted in the Chinese EPA guidelines (NEPA scheme). Difference in the surface concentration of air pollutant simulated under different atmospheric stability with the four schemes, respectively, was analyzed. In general, under unstable and neutral conditions, differences from the four schemes are relatively small. However, under stable condition, the AERMOD scheme tends to overestimate the concentrations compared with the Briggs and NEPA schemes. This is possibly because the AERMOD scheme cannot sufficiently recognize the contribution of local turbulence.