|dc.description.abstract||Taiwan is located to the southeast of the East Asian continent. In winter, the northeast monsoon can transport air pollutants from East Asia to Taiwan. In spring, the prevailing westerlies can transport the biomass burning emitted pollutants from the Indochina Peninsula to the high elevation mountain areas of Taiwan. This long-range transport of pollutants can influence the air quality, environment, and ecosystem of Taiwan. Lulin Atmospheric Background Station (LABS, 2862 m a.s.l.) was established in central Taiwan in 2006 to study the impact of regional and long-range transported air pollutants on the environment and ecosystem in Taiwan. Therefore, the location of LABS is ideal for the study of characterizing the export of mercury(Hg) from the East Asian continent to its downwind region.
In 2010, mean concentrations(±SD) of gaseous element mercury(GEM), reactive gaseous mercury(RGM) and particulate mercury(PHg) measured at LABS were 1.56(±0.42) ng m-3, 13.95(±31.32) pg m-3 and 0.71(±2.65) pg m-3, respectively. Mean concentrations(±SD) of carbon monoxide(CO) and ozone(O3) were 143(±67) and 33.8(±15.0) ppb, respectively. Good positive correlation between GEM and CO(r = 0.78) indicated that the variation in GEM concentrations was related to anthropogenic activities. The volume-weighted mean (VWM) concentration of mercury in rainwater was 8.8 ng L-1. Total precipitation depth was 3173.2 mm. Wet deposition flux was 33.7µg m-2. Total dry deposition flux was 69.5 μg m-2, with 58.8, 10.6 and 0.1 μg m-2 contributed by GEM, RGM, and PHg, respectively. Wet deposition flux was higher than dry deposition flux in summer because of higher rainfall amount. The opposite was observed in the other seasons. It has been suggested that the dry deposition flux was more important in North America (Temperate Zone). Mean dry and wet deposition fluxes in North America were about 15 and 10 µg m-2, respectively. The wet deposition flux in North America is about one-third of Mt. Lulin’s (Subtropical Zone) value because of higher rainfall in Taiwan.