HR: 1340h
AN: A53C-1350    [Abstracts]
TI: Measurements of Atmospheric Mercury at a High Elevation Site (Lulin Atmospheric Background Station, LABS) in Taiwan
AU: * Sheu, G
EM: grsheu@atm.ncu.edu.tw
AF: Department of Atmospheric Sciences and Institute of Atmospheric Physics, National Central University, 300 Jhongda Road, Chung-Li, 32001, Taiwan
AU: Lee, C
EM: leegino_bi@yahoo.com.tw
AF: Department of Atmospheric Sciences and Institute of Atmospheric Physics, National Central University, 300 Jhongda Road, Chung-Li, 32001, Taiwan
AU: Lin, N
EM: nhlin@cc.ncu.edu.tw
AF: Department of Atmospheric Sciences and Institute of Atmospheric Physics, National Central University, 300 Jhongda Road, Chung-Li, 32001, Taiwan
AB: Taiwan is located on the edge of the west Pacific Ocean and to the downwind side of East Asia, which is the largest anthropogenic mercury (Hg) emitting region globally. It has been demonstrated that the environmental quality of Taiwan can be influenced by regional Asian atmospheric pollution events, such as acid deposition, dust storm, and biomass burning. Therefore, Taiwan could also be under the influence of the East Asian Hg emissions. As a result, continuous atmospheric Hg measurements have been conducted at Lulin Atmospheric Background Station (LABS, 2862 m a.s.l.) since April 13, 2006 to study the long-range transport and transformation of atmospheric Hg. Three types of atmospheric Hg, including gaseous elemental Hg (GEM), reactive gaseous Hg (RGM), and particulate Hg (PHg), are measured using the Tekran 2537A/1130/1135 speciation system. Here we report the atmospheric Hg data collected between April, 2006 and April, 2007. The average GEM, RGM, and PHg concentrations were 1.83(±0.65) ng m^-3, 17.85(±18.70) pg m^{- 3}, and 6.12(±7.36) pg m^-3, respectively. Seasonal variability in GEM concentration was evident with higher GEM concentrations between fall and spring. The highest monthly GEM average of 2.43 ng m^-3 was observed in October, 2006. GEM concentrations were usually low in summer months with the lowest monthly average of 1.10 ng m^-3 in July, 2006. Backward trajectory analysis indicated change in air mass origins among seasons. In summer (May ~ July), air masses were mainly from the Pacific Ocean with minimal land influence. On the other hand, between fall and spring, air masses were more or less under the influence of East Asia continent. These results suggested that Taiwan could be impacted by East Asia Hg emissions between fall and spring. Also, spikes of RGM were frequently detected between midnight and early morning with concurrent decreases in GEM and relative humidity and increases in ozone concentrations, suggesting the oxidation of GEM and formation of RGM in free troposphere.
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0368 Troposphere: constituent transport and chemistry
DE: 0432 Contaminant and organic biogeochemistry (0792)
DE: 0478 Pollution: urban, regional and global (0345, 4251)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting