Volatile hydrocarbons (C6–C10) measurements at remote sites of Taiwan during the Pem-West a experiment (1991)

For the first time, ambient volatile hydrocarbons in the range of C6–C10 were measured at four remote sites of Taiwan in the period of June 1991 to October 1992, and the data collected in Kenting was a part of the Pacific Exploratory Mission-West A experiment sponsored by National Aeronautics and Space Administration (NASA). All the concentration of target hydrocarbons except toluene lower to sub-ppb range were observed at four sampling sites. Toluene was shown the higher standard deviation means the more significant the diurnal variation during sampling period in Lanyu. The very simple hydrocarbons patterns at each site presented the lack of direct anthropogenic pollution source in the remote regions. The most prevalent component was generally toluene followed by the xylene isomers and benzene. Results obtained from Kenting indicated at least three different mass types were observed at the site. The average concentrations (ppbv) determined for benzene and toluene in the continental outflow were 0.25±0.05 and 0.13±0.05, respectively. In the marine boundary layer were 0.15±0.06 (benzene) and 0.18±0.11 (toluene) and 0.66±0.11 (benzene) and 1.08±0.42 (toluene) in the urban plume. The data collected indicated that the East Asia regional sources of pollution enhanced the average trace gas concentrations in the background atmosphere.