Seasonal and diurnal measurements of carbon monoxide and nonmethane hydrocarbons at Mt. Wilson,California: Indirect evidence of atomic Cl in the Los Angeles basin |
| |
| Authors: | Katrine A. Gorham Nicola J. Blake Richard A. VanCuren Henry E. Fuelberg Simone Meinardi Donald R. Blake |
| |
| Affiliation: | 1. Ministry of Education Key Laboratory for Earth System Modeling, Center for Earth System Science, Tsinghua University, Beijing 100084, China;2. Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS B3H 4R2, Canada;3. State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China;4. Harvard–Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA;5. Institute of Energy, Environment and Economy, Tsinghua University, Beijing 100084, China;6. Key Laboratory of Atmospheric Chemistry (LAC), Institute of Atmospheric Composition, Chinese Academy of Meteorological Science, Beijing 100081, China;7. Laboratory for Climate and Ocean–Atmosphere Studies, Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing 100871, China |
| |
| Abstract: | We present a study of the seasonal and diurnal variability of carbon monoxide and selected volatile organic compounds in the Los Angeles area. Measurements were made during four different nine-day field campaigns in April/May, September, and November, 2007, and February, 2008, at the Mt. Wilson sampling site, which is located at an elevation of approximately 1700 m in the San Gabriel Mountains overlooking Pasadena and the Los Angeles basin. The results were used to characterize the Mt. Wilson site as a representative location for monitoring integrated Los Angeles basin emissions, and, by reference to carbon monoxide emissions, to estimate average annual emissions. The considerable seasonal variability of many hydrocarbons, in both their measured mixing ratios and their relationship to carbon monoxide, was indicative of variable source strengths. Most interestingly, perturbation of C4 hydrocarbon ratios suggested an enhanced role for chlorine chemistry during the month of September, likely as the result of Los Angeles’ coastal location. Such coastal influence was confirmed by observations of enhanced mixing ratios of marine halocarbons, as well as air mass back trajectories. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
