关键词: 珠江三角洲(珠三角), O₃, PM10, 污染气象条件

Abstract: The Community Multi-Scale Air Quality (CMAQ) modeling system was applied to simulate the meteorology field, O₃ and PM10 in the Pearl River Delta (PRD) region in the autumn of 2008, in order to elucidate the impact of the typical meteorological conditions on the O₃ and PM10 pollution episodes. It was found that PRD pollution characteristics presents periodic variation affected by cold air processes in the autumn of 2008. In general, good air quality was presented when cold air passing through while serious pollution was took place before and after the cold air invasion. 1) Before the cold air invasion, when the weather system “cold front front part” was presented, the height of the mixing layer was often low due to a presence of temperature inversion. Therefore, the PM10 emitted or formed at night was continuously accumulated in the morning hours causing the air pollution in northern and central PRD; the afterwards transport of the O₃ during daytime and PM10 during nighttime with northern wind would cause the air pollution in southern PRD. 2) Before the cold air invasion, when the weather system “high-pressured base” was presented, an inversion layer was built up to prevent vertical mixing; both O₃ and PM10 was then mainly horizontally transported with northeasterly wind; consequently forming air pollution in southwestern PRD. 3) After the cold air invasion, under the control of a ridge high pressure type of weather condition, temperature inversion was built up near the surface and a stagnant condition was presented; thus, O₃ and PM10 was trapped in the source regions such as western, northwestern and central PRD, resulted in serious local pollutions.

Key words: Pearl River Delta (PRD), O₃, PM10, meteorological conditions