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 less than 1km. Thirdly

the aerosol concentrations based on atmospheric composition monitoring network data showed the largest values since the establishment of the stations

greatly exceeding the coordinate default preset limit.