Synoptic weather patterns associated with NO{sub x} pollution episodes in Hong Kong urban areas
- Hong Kong Polytechnic Univ., Kowloon (Hong Kong). Dept. of Civil and Structural Engineering
This study aims to find out the relationship between synoptic weather patterns and the air quality in HK urban areas. The air pollutants in HK are mainly vehicular emissions. Therefore, in this study, NO{sub x} (NO + NO{sub 2}) was used as an indicator of the urban air quality. Three years record of NO{sub x} concentration was examined and high NO{sub x} episodes were selected. 70% of high NO{sub x} pollution episodes were found to be related to calm or light wind conditions. Under low wind speed and stable conditions, both horizontal and vertical dispersion of local air pollutants are prohibited, hence air pollutants accumulate to harmful levels. The synoptic weather patterns on the episode days associated with calm conditions were investigated. The authors; found that the existence of: (1) a tropical cyclone over the NW Pacific Ocean, and HK is under the influence of its periphery subsiding air; (2) a weak continental high-pressure system with central highest pressure less than 1030hPa; and (3) a low-pressure trough being close to HK, were likely to give rise to calm conditions and hence NO{sub X} episodes in urban areas.
- OSTI ID:
- 679435
- Report Number(s):
- CONF-980632-; TRN: IM9940%%254
- Resource Relation:
- Conference: 91. annual meeting and exhibition of the Air and Waste Management Association, San Diego, CA (United States), 14-18 Jun 1998; Other Information: PBD: 1998; Related Information: Is Part Of Proceedings of the 91. annual meeting and exhibition. Bridging international boundaries: Clean production for environmental stewardship; PB: [5000] p.
- Country of Publication:
- United States
- Language:
- English
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