深圳市夏季臭氧污染研究

以2009年8月为例分析了深圳市夏季臭氧污染情况及污染气象特征,基于二维空气质量模式对臭氧污染控制进行数值模拟.结果表明:深圳市8月各监测点均存在臭氧超标现象,污染形势严峻;副热带高压控制和热带气旋外围下沉气流是造成夏季出现高浓度臭氧的主要天气过程,此时大气边界层混合层高度在500～800 m,且近地面风速约在5 m/s以内,不利于污染物扩散;臭氧的生成受前体物挥发性有机物(VOC)和氮氧化物(NOx)排放的共同影响,其中VOC排放的影响较大,深圳市臭氧控制应以降低VOC排放量为重点,模拟得出对VOC和NOx按2.5∶1～4.0∶1的比例协同减排可有效降低臭氧污染.

Ozone Pollution in Summer in Shenzhen City

To investigate summer ozone pollution and meteorological characteristics in Shenzhen City,China,a case study was conducted in August 2009,and a two-dimensional air quality model was applied to simulate the effects of ozone control.The results indicated that the maximum hourly ozone concentrations in summer at all the monitoring stations in Shenzhen City exceeded the national standard.The major weather processes causing high ozone concentration were the subtropical high pressure and before the landfall of tropical cyclones,during which the mixing layer was about 500-800 meters high and the wind speed below 1000 meters was around 5 ms.These conditions significantly prevented the local pollutants from spreading.According to the results of the modeling study,ozone concentration was affected by emissions of both volatile organic compounds(VOC) and nitrogen oxides(NOx),and the effect of VOC emissions was greater than that of NOx.Therefore,to control ozone pollution in Shenzhen,the reduction of VOC emissions should be emphasized.The results of the simulation also suggested that the ozone concentration will be decreased effectively by reducing the emissions of VOC and NOx by a ratio of 2.5∶1 to 4.0∶1.