低层通风量及逆温条件对浙江省空气质量的影响分析

利用高时空分辨率的ERA-Interim资料，结合环保局空气质量监测数据，分析了1000 m以下低层大气扩散能力和大气层结条件对浙江省大气环境质量的可能影响.结果表明：浙江省700 m以下的大气扩散能力对全省大部地区的空气质量有明显影响，部分地区700~1000 m的大气扩散能力对空气质量也有一定的影响.但位于沿海的舟山，仅300 m以下的大气扩散能力对空气质量有显著的影响.将低层大气扩散能力分别与逆温层高度、空气质量做相关性分析，结果显示通过显著性检验的影响区域和影响高度有很好的一致性，说明三者之间存在密切的联系.逆温层高度越低，低层大气扩散能力越弱，空气质量越差，严重污染天气出现时常常伴随着强度较强或贴近地面的逆温发生.浙江省大气层结大部分时间处于中性状态，当大气层结转为较稳定时，污染物不易扩散稀释，空气污染较易发生.

The impact analyses of low-level ventilation and temperature inversion on air quality in Zhejiang Province

In this study, high resolution ERA-Interim data, as well as air quality data from Environmental Protection Agency were used, to analyze the potential effects of low-level air diffusion capacity below 1000 m and atmospheric stratification on air quality in Zhejiang Province. Results show that the air diffusion capacity below 700 m has important impacts on the air quality in most parts of Zhejiang, and in some areas, the air diffusion capacity of 700~1000 m also has effects on air quality. However, in Zhoushan, a coastal city, only the air diffusion capacity below 300 m has important impacts on air quality. We conduct correlation analyses between low-level air diffusion capacity and height of temperature inversion layer, as well as low-level air diffusion capacity and air quality. Results show that, the high impact areas and influence height of the above two processes are in good consistency, showing the close correlations between low-level air diffusion capacity, height of temperature inversion layer, and air quality. Low temperature inversion layer height leads to weak low-level air diffusion capacity, and the consequent low air quality. The occurrence of serious air pollution is often associated with strong temperature inversion or inversion close to the ground. In Zhejiang Province, the atmospheric stratification is in neutral states in most of the time. When the atmosphere is in a more stable state, the pollutants would be not easily diffused or diluted, therefore, the air pollution is more likely to occur.