香港地区一次光化学污染过程的特征分析

STUDY ON THE CHARACTERISTICS OF A PHOTOCHEMICAL POLLUTION EPISODE IN HONG KONG

对2000年3月28-31日发生在香港地区的一次光化学污染过程进行了分析。在这次过程中,O3、NO2、CO、RSP、SO2的最大浓度分别达到175.2μg/m3,333.5μg/m3,5405μg/m3,349.3μg/m3,132.8μg/m3,污染持续时间三天,影响范围覆盖香港全境。利用同步的气象资料和大气污染监测数据,进行了浓度变化分析、气象条件分析、局地光化学机制分析和输送机制分析。结果揭示了这次污染过程的基本特征,并指出造成这次大气污染的可能原因:晴天高温、低湿的气象条件和局地污染物的排放对此次光化学烟雾的形成有重要作用;外地污染物的输送对污染形成也有一定贡献。香港地区所处的地理位置、城市布局和交通状况有利于光化学污染的形成。

We have presented here a study on the characteristics of a photochemical pollution episode in Hong Kong during Mar.28th-Mar.31th, 2000. In this episode, the maximum concentrations of O3, NO2, CO, RSP, SO2 reach 175.2 μg/m3, 333.5μg/m3, 5405 μg/m3, 349.3 μg/m3 and 132.8μg/m3, respectively. The episode lasts three days in areas of urban Hong Kong. The synchronous meteorological data and air monitoring data are adopted for the analysis with focuses on concentration variation, meteorological pattern, the mechanisms of local photochemical pollution and regional transport. Investigations have revealed the principal characteristics of this episode. The possible reasons can be that clear sky with high temperature and low humidity as well as local emissions are attributable to the episode. Also, regional transport plays an important role on the episode. It indicates that the geographical location, urban building and traffic status of Hong Kong are beneficial to the formation of photochemical pollution.