The seasonal evolution of NMHCs and light alkyl nitrates at middle to
was designed to follow the role of photochemistry in the evolution of the springtime maximum of tropospheric ozone (O3) in the Northern Hemisphere (NH) at high latitudes. Determination of the composition and seasonal evolution of volatile organic carbon (VOC) species, which take part in and are good...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.523.1048 http://infohost.nmt.edu/~oliver/BlakeTOPSE2003.pdf |
| Summary: | was designed to follow the role of photochemistry in the evolution of the springtime maximum of tropospheric ozone (O3) in the Northern Hemisphere (NH) at high latitudes. Determination of the composition and seasonal evolution of volatile organic carbon (VOC) species, which take part in and are good indicators for photochemical processes in the troposphere, was an important part of this study. We report measurements of a large number of C2–C10 nonmethane hydrocarbons (NMHCs), selected C1–C2 halocarbons, and C1–C4 alkyl nitrates. These gases were quantified in whole air samples collected aboard the National Center for Atmospheric Research (NCAR) C-130 aircraft at altitudes between 30 m and 8 km. Seven TOPSE sampling trips were flown between early February and mid-May 2000 covering the region from Colorado (40N) to Churchill (in Manitoba, Canada), Thule (in northern Greenland), and as far north as 85N. These measurements represent the most comprehensive spatial characterization of the North American Arctic to date and revealed strong latitudinal, vertical, and temporal NMHC gradients. In the midtroposphere north of Churchill (58N), NMHCs decreased by 6.2 ppbC between February and May (1.6 ppbC month1) and the magnitude of this change diminished with altitude. Over |
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