气象因素对环境空气质量达标的影响分析

以天津市为例,分析地面风场、大气层结及天气形势等主要污染气象参量的特征及其与环境空气质量的相关关系;估算高、低污染潜势的天气背景对大气污染物浓度的影响幅度;提出在天气气候分类的基础上,建立气象条件标准化分级,评估气象条件对环境空气质量影响水平的方法。研究表明:天津市采暖季高污染的天气形势出现的频率约为34%,而非采暖季高污染的天气形势出现的频率约为16%,ISCLT3模型模拟结果显示相应于相同的污染源排放数据库由于采暖季和非采暖季气象条件不同引起的SO2全市平均浓度的差异约在10%以上。污染源源强相对稳定的条件下,高污染潜势的天气背景对空气污染的加剧作用大于低污染潜势的天气背景对空气污染的减轻作用。

Meteorological Effects on Ambient Air Quality to Come up to National Standard

Taking Tianjin as an example,the characteristics of three major meteorological parameters(surface wind,atmospheric stratification,as well as weather situation) and their correlations with ambient air quality were analysed.Variable concentration ranges of air pollutants in the presence of synoptic types with different polluted potential were then computed.Based on synoptic climatological approach and meteorological condition grade,a method for evaluating the meteorological effect level in ambient air quality was presented.The study showed that occurrence frequency of weather type with high polluted potential was about 34% in the heating season,while the occurrence frequency was 16% in the non-heating season.Atmospheric dispersion conditions were different between heating season and non-heating season.Numerical simulation with ISCLT3 model reflected that the discrepancy in average concentrations of SO_2 over Tianjin due to different meteorological conditions in the heating season and in the non-heating,for the same sources emission database,was greater than 10%.Under the condition which sources emission was relatively stable,in the same season,worsening effect of synoptic types with high polluted potential was greater than mitigation effect of synoptic types with low polluted(potential.)