利用后向轨迹模式研究TRACE-P期间香港大气污染物的来源

INVESTIGATION INTO THE SOURCE OF AIR POLLUTANTS TO HONG KONG BY USING BACKWARD TRAJECTORY METHOD DURING THE TRACE-P CAMPAIGN

利用Hysplit4.7轨迹模式和2001年3月NCEP再分析气象资料,计算2001年3月TRACE-P期间抵达香港地区的后向气流轨迹,并分析香港地区大气输送特征。对轨迹进行聚类分析后得到到达香港的6类典型气团。结合香港鹤咀测站所测量的大气污染物的浓度,进一步分析不同来源气团的化学特征。抵达香港的气流轨迹结果表明来自大陆的气团占47.5%,局地输送性气团占34.6%,海洋性气团占18.7%。鹤咀测站的污染性气体O3、SO2、CO在大陆气团影响下的平均浓度分别为31.1、3.0、486.1μg/m3;在海洋性气团影响下分别为20.0、1.0、319.4μg/m3;在局地输送气团影响下分别为20.0、1.2、308.0μg/m3。

Using the Hysplit4.7 Model and NCEP reanalysis data for March 2001, the backward trajectories arriving in Hong Kong are calculated and the atmospheric transport characteristics in Hong Kong are discussed in this paper. According to the cluster analysis for trajectories, six categories of air masses are obtained that eventually arrive in Hong Kong. Using the concentration of air pollutants measured at Cape D＇Aguilar station during the TRACE-P Campaign, we get different chemical characteristics for different air masses. The results show that 47.5% of the trajectories come from China's Mainland, 34.6% of them from local sources in Hong Kong and 18.7% of them from maritime area. The Cape D＇Aguilar station＇s average concentrations of 03, SO2 and CO are 31.1, 3.0, 486.1 μg/m^3, respectively, with the effect of continental air masses, 20.0, 1.0, 319.4 μg/m^3, respectively, with the effect of maritime air masses, and 20.0, 1.2, 308.0 μg/m^3, respectively, with the effect of local air masses.