HR: 1340h
AN: A13C-0946    [Abstracts]
TI: Intercomparison of two Semi-continuous PM2.5 Sulfate and Nitrate Instruments at an Urban Site in Hong Kong
AU: * Wu, W
EM: 03902479r@polyu.edu.hk
AF: Hong Kong Polytechnic University, Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hong Kong, China
AU: Wang, T
EM: cetwang@polyu.edu.hk
AF: Hong Kong Polytechnic University, Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hong Kong, China
AB: Sulfate and nitrate aerosols have important implications for human health, visibility, and climate. Understanding their formation processes in the atmosphere requires the use of time-resolved instruments. In this study, an informal intercomparison between Rupprecht & Patashnick sulfate and nitrate monitors (R&P8400S and R&P8400N) and an Ambient Ion Monitor (URG9000B) were conducted at an urban site in Hong Kong (Tsuen Wan) during January-March 2005. Both the semi-continuous instruments were set at a 1 hour time resolution for measuring sulfate and nitrate in PM2.5. Results showed that the general trends for sulfate and nitrate were similar from the two sets of instruments. However, the discrepancy, in terms of absolute concentrations, was found between the two. For the whole measurement periods, average concentration of sulfate was 17.9ug/m3 and 13.3ug/m3, for R&P8400S and URG9000B, respectively, while average concentration of nitrate was 2.8ug/m3 and 3.4ug/m3. The correlation coefficient for sulfate and nitrate were 0.6 and 0.8, respectively. The possible reasons for the discrepancy are discussed with the use of concurrent PM2.5 and carbon measurements.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0335 Ion chemistry of the atmosphere (2419, 2427)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005