中文摘要：

由于经济规模迅速扩大和城市化进程加快，大气气溶胶污染日趋严重，由细粒子气溶胶造成的能见度恶化事件越来越多，这些人类活动排放的污染物，可形成灰霾天气致使能见度下降。2009年11月23—29日，在珠三角地区发生了一次典型的严重灰霾天气过程，是近10年来最严重的灰霾天气过程之一。从天气分析、流场分析、遥感分析和气溶胶物理化学特征分析，探讨了这次过程的成因，结论是这次灰霾过程具有持续时间长、范围广、强度大的特点。这次严重灰霾过程持续7d，仅次于2004年1月3—10日持续8d的过程；范围广，笼罩整个珠三角，多个台站出现小于1km的低能见度事件；强度大，珠三角大气成分监测网数据，都出现多项建站以来最强值，许多指标都超过缺省预设的坐标上限，超标均以倍数计。

英文摘要：

With the rapid economy expansion and urbanization, atmospheric aerosol pollution is getting serious, which leads to a number of visibility degradation events caused by increasing fine particle aerosol. These pollutant emissions from human activities produce haze and cause low visibility. During 23 - 29 November 2009 , an extremely severe haze process over the Pearl River Delta region was observed, which is one of the worst climate events in the past decade. In this paper, the causes of this particular event were discussed based on weather analysis, flow field analysis, remote sensing analysis, and physical and chemical characteristics of aerosols. This event was characterized by a long duration, a wide range influence and strong strength. Firstly, the event lasted for 7 days, just shorter than that one lasting for 8 days occurred during 3 - 10 January 2004. Secondly, it enveloped the entire Pearl River Delta,making the visibility of a number of stations atmospheric composition monitoring network less than 1 km. Thirdly, the aerosol data showed the largest values since stations, greatly exceeding the coordinate default preset limit.