The understanding of the source identification of pollutants is of great interest in environmental studies today due to the health impact caused by airborne pollutants (SO2, NO, NO2, CO and RSPs, etc). A study of concentrations of SO2 and RSP has been performed in Hong Kong. The work reported here develops an improved circular pollution wind map, and combines with both the principal component analysis (PCA) and singular value decomposition (SVD) techniques to analyze the pollutant data recorded in 14 air quality monitor stations from 2000 to 2002 using hourly winds measured at Tap Shek Kok (TSK). The variations of SO2 over Hong Kong were discussed from the standpoint of monthly variations, inter-annual variabilities and spatial distributions and wind effects. The PCA result is able to i...[ Read more ]

The understanding of the source identification of pollutants is of great interest in environmental studies today due to the health impact caused by airborne pollutants (SO2, NO, NO2, CO and RSPs, etc). A study of concentrations of SO2 and RSP has been performed in Hong Kong. The work reported here develops an improved circular pollution wind map, and combines with both the principal component analysis (PCA) and singular value decomposition (SVD) techniques to analyze the pollutant data recorded in 14 air quality monitor stations from 2000 to 2002 using hourly winds measured at Tap Shek Kok (TSK). The variations of SO2 over Hong Kong were discussed from the standpoint of monthly variations, inter-annual variabilities and spatial distributions and wind effects. The PCA result is able to identify two dominant modes of SO2 variations. The first mode is associated with weak southerlies and southwesterlies, and is localized around the Kowloon peninsula. This may be a consequence of the surrounding complex terrain. Analysis of speciated PM10 data shows that this mode is associated with local SO2 emissions by residual oil combustion from marine sources at or near the container terminal in Kwan Chung (KC). The second mode is associated with moderate to strong northwesterlies, and is affected most of the area in Hong Kong. Analysis of speciated PM10 data suggests that this mode is associated with a mixture of various sources, and mainly related to the regional transport from the northwest. In addition, the proportion of the total SO2 concentrations contributed by each of the source regions was quantitatively estimated by SVD. It is found that residual oil combustion from marine vessels at or near Kwai Chung terminal container port and power plant are responsible for 36% and 7% of the total SO2 concentrations in the urban air of Hong Kong, respectively. It means that the contribution of marine sources from container port is five times more than power plants. We also find that the seasonal variation of element carbon in PM10 species is high in summer and low in winter from the container port, which helps us further understand its characteristics over Hong Kong.