Diurnal cycles of short-lived tropospheric alkenes at a north Atlantic coastal site |
| |
| Institution: | 1. School of Environmental Science and Engineering, Shandong University, Jinan 250100, China;2. Shandong Provincial Environmental Information and Monitoring Centre, Jinan 250101, China;3. Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse, NY 13210, USA;4. Department of Earth and Atmospheric Science, University of Houston, Houston, TX 77204, USA;5. Environmental Monitoring Central Station of Shandong Province, Jinan 250101, China;6. Department of Surgery, State University of New York, Upstate Medical University, Syracuse, NY 13210, USA;1. Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA;2. Research Center for Environmental Changes, Academia Sinica, Taipei 115, Taiwan;3. Southwest Research Institute, Boulder, CO 80302, USA;4. George Mason University, Fairfax, VA 22030, USA;5. Southwest Research Institute, San Antonio, TX 78238, USA;6. University of Texas at San Antonio, San Antonio, TX 78249, USA;7. National Aeronautics and Space Administration, Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA;8. The Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA |
| |
| Abstract: | Observation of diurnal cycles in atmospheric concentrations of reactive alkenes are reported from measurements performed at a North Atlantic coastal site (Mace Head, Eire 53°19′34″N; 9°54′14″W). Species seen to exhibit distinct cycles included isoprene, ethene, propene, 1-butene, iso-butene and a substituted C6 alkene. Five hundred and thirty air mass classified measurements were performed over a 4 week period at approximately hourly frequency and demonstrate that during periods when air flow resulted from unpolluted oceanic regions a clear daily cycle in concentrations existed, peaking at around solar noon for all species. These observations support the proposed mechanism of production via photochemical degradation of organic carbon in sea water. The observed concentrations showed strong correlation (propene R2>0.75) with solar flux, with little relationship to other meteorological or chemical parameters. The species’ short atmospheric lifetimes indicate that the source of emission was from local coastal waters within close proximity of the sampling site. At solar noon concentrations of reactive alkenes from oceanic sources were responsible for up to 88% of non-methane hydrocarbon reaction with the hydroxyl radical at this coastal marine site. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
