2006年12月14～15日上海大雾及大气污染过程分析

Analysis on the Heavy Fog and Atmospheric Pollution Process in Shanghai During December 14-15th,2006

2006年12月14～15日上海、南京、合肥等城市出现了较长时间的大雾和轻度污染过程。运用GTS地面和探空资料、NCEP/NCAR再分析资料,从天气形势分析、水汽条件、动力因子、温度层结、空气质量等方面,对此次大雾过程的成雾条件及大气污染对持续大雾的贡献进行分析。结果表明,1000hPa水汽通量散度(FD)、1000hPa垂直速度(ω)、500hPa和1000hPa散度差(ΔDIV)与能见度无显著相关,近地面相对湿度(RH)与能见度呈明显反相关,近地面温度递减率(γ)与能见度呈明显正相关,可以把可RH≥85%、γ<0.2℃/100m作为大雾形成的必要条件。另外航空能见度最低值与日平均API指数呈强烈的反相关,可以把"日平均API指数上升达到150"作为上海虹桥机场出现大雾的一个重要的判断条件。

A process of continuous heavy fog and air pollution occurred in the eastern china including Shanghai,Nanjing,Hefei etc. during 14-15th,December,2006. Based on the GTS synoptic data,sounding data and NCEP/NCAR reanalyzed dataset,from the aspects of the weather situation,vapor condition,dynamic factor,temperature stratification,and air quality,the contribution of foggy conditions and atmospheric pollution in the fog process to continuous heavy fog were analyzed. The results showed that 1 000 hPa fluid flux divergence（FD）,vertical velocity（ω） and divergence difference（ΔDIV） between 1 000 hPa and 500 hPa had not significant correlation with visibility,while relative humidity（RH） near ground had significant negative correlation,temperature lapse rate（γ）near ground had significant positive correlation,therefore,RH≥85%、γ0.2 ℃/100 m could be regarded as the necessary conditions of fog formation. In addition,the lowest air visibility had intense negative correlation with daily averaged API in the meantime,＂API rising up to 150＂ could be an important criterion of fog formation in Shanghai Hongqiao international airport.