Institute of Environment, Energy and Sustainability, The Chinese University of Hong Kong, Sha Tin, N.T., Hong Kong.
Department of Geography and Resource Management, The Chinese University of Hong Kong, Sha Tin, N.T., Hong Kong.
Sci Total Environ. 2018 Mar 15;618:132-141. doi: 10.1016/j.scitotenv.2017.11.001. Epub 2017 Nov 8.
Trans-boundary air pollution (TAP) is a crucial factor affecting air quality, and its contribution may vary over time and differ under various atmospheric conditions. This study firstly applies an integrated statistical scheme to estimate the contributions of TAP and local sources to air pollutants in a city, and then investigate the influences of tropical cyclones (TC) on TAP. Hong Kong is chosen as an example because of its significant and special TAP characteristics. This study focuses on four major air pollutants, namely, respirable and fine suspended particulates (RSP/PM and FSP/PM), sulfur dioxide (SO), and nitrogen dioxide (NO), from 2002 to 2013. Our results show that, on average, TAP is the major contributor of the annual RSP, FSP, SO, and NO in Hong Kong. We estimate that when a TC is approaching, the increase in pollutant concentration in Hong Kong is mainly due to the increase in TAP contribution by the strengthened northerly wind at higher level of atmosphere (≥900hPa). These changes are accompanied by decreases in precipitation and increases in northerly/north-easterly wind, which may prolong the lifetime of pollutants, enhancing pollutant transport from mainland China to Hong Kong.
跨境空气污染（TAP）是影响空气质量的一个关键因素，其贡献随时间变化而变化，并且在不同的大气条件下也有所不同。本研究首先应用综合统计方案来估计城市中 TAP 和本地源对空气污染物的贡献，然后研究热带气旋（TC）对 TAP 的影响。选择香港作为研究对象，是因为其具有显著而特殊的 TAP 特征。本研究重点关注 2002 年至 2013 年期间的四种主要空气污染物，即可吸入和细悬浮颗粒物（RSP/PM 和 FSP/PM）、二氧化硫（SO）和二氧化氮（NO）。我们的结果表明，TAP 是香港年 RSP、FSP、SO 和 NO 的主要贡献者。我们估计，当 TC 逼近时，香港污染物浓度的增加主要是由于高层大气（≥900hPa）上风增强导致 TAP 贡献的增加。这些变化伴随着降水减少和北风/东北风增加，这可能会延长污染物的寿命，增强污染物从中国大陆向香港的输送。
