Analysis of a high PM(10) episode observed at a coastal site nearby Shanghai, China.

A high PM(10) episode observed at a coastal site nearby Shanghai during 18-19 January 2007 was analyzed in this study. The maximum hourly averaged PM(10) concentrations for the 2 days were 0.58 and 0.62 mg/m(3), respectively. The meteorological condition during the episode was favorable for air pollution with large-scale stagnation. There was no dispersing effect by high wind, no scavenging function by precipitation, and no diluting process by clean marine air during the episode. The trajectories for 16-19 January all came from the northern region and kept in low levels, and during the episode peak time, from the morning of 18 to the morning of 19 January, trajectories all came from the northern inland areas and had passed over the coastal region of Jiangsu province before arriving at the site. The variation of the air pollution indexes (APIs) in the cities located in the upwind direction of the site during the episode days clearly shows a process of large-scale air pollution from north to south. The liner correlation coefficient for PM(10) and SO(2) concentrations is 0.774 during the episode, while for PM(10) and CO, it even reaches 0.995, which indicated that the high PM(10) was mainly emitted from the coal burning for domestic heating in winter. Therefore, the observed episode was caused by the transport of domestic heating pollutants accumulated in the boundary layer from northern continental areas.