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| Titel |
Lightning-produced NO2 observed by two ground-based UV-visible spectrometers at Vanscoy, Saskatchewan in August 2004 |
| VerfasserIn |
A. Fraser, F. Goutail, C. A. McLinden, S. M. L. Melo, K. Strong |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 7, no. 6 ; Nr. 7, no. 6 (2007-03-28), S.1683-1692 |
| Datensatznummer |
250004838
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| Publikation (Nr.) |
 copernicus.org/acp-7-1683-2007.pdf |
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| Zusammenfassung |
| Ground-based measurements of ozone and NO2 differential slant columns by the SAOZ
(Système d'Analyse par Observations Zénithales) and UT-GBS (University of
Toronto Ground-Based Spectrometer) instruments during the MANTRA 2004 field
campaign are presented herein. During the afternoon of 28 August, a
thunderstorm passed over the instruments, which were installed at Vanscoy,
Saskatchewan (52° N, 107° W). Enhanced differential slant columns of ozone and
NO2 were observed by both instruments during the storm, with maximum
values of two and 25 times the expected clear sky columns, respectively. The enhanced
ozone differential slant columns are primarily due to the longer path traversed by the
solar radiation caused by multiple scattering inside the thick cloud layer
associated with the thunderstorm. The enhanced NO2 columns are partly attributed
to NOx production by lightning. Two new methods are used to separate
the NO2 enhancements into contributions from the longer path length and
production by lightning. Combining the observed excess NO2 with lightning
flash data from the Canadian Lightning Detection Network and Environment
Canada Doppler radar measurements, the production of NO2 molecules per
lightning flash is determined. Using these two methods, the best estimate of
the production rate is found to be (7.88±2.52)×1026 molecules
NO2/flash from the UT-GBS and (6.81±2.17)×1026 molecules
NO2/flash from SAOZ. These results are consistent with the range of previous estimates reported in the literature. |
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