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| Titel |
The global lightning-induced nitrogen oxides source |
| VerfasserIn |
U. Schumann, H. Huntrieser |
| 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. 14 ; Nr. 7, no. 14 (2007-07-24), S.3823-3907 |
| Datensatznummer |
250005141
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| Publikation (Nr.) |
 copernicus.org/acp-7-3823-2007.pdf |
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| Zusammenfassung |
| The knowledge of the lightning-induced nitrogen oxides
(LNOx) source is important for understanding and predicting the
nitrogen oxides and ozone distributions in the troposphere and their trends,
the oxidising capacity of the atmosphere, and the lifetime of trace gases
destroyed by reactions with OH. This knowledge is further required for the
assessment of other important NOx sources, in particular from aviation
emissions, the stratosphere, and from surface sources, and for understanding
the possible feedback between climate changes and lightning. This paper
reviews more than 3 decades of research. The review includes laboratory
studies as well as surface, airborne and satellite-based observations of
lightning and of NOx and related species in the atmosphere. Relevant
data available from measurements in regions with strong LNOx influence
are identified, including recent observations at midlatitudes and over
tropical continents where most lightning occurs. Various methods to model
LNOx at cloud scales or globally are described. Previous estimates are
re-evaluated using the global annual mean flash frequency of 44±5 s−1
reported from OTD satellite data. From the review, mainly of
airborne measurements near thunderstorms and cloud-resolving models, we
conclude that a "typical" thunderstorm flash produces 15 (2–40)×1025
NO molecules per flash, equivalent to 250 mol NOx or 3.5 kg
of N mass per flash with uncertainty factor from 0.13 to 2.7. Mainly as a
result of global model studies for various LNOx parameterisations
tested with related observations, the best estimate of the annual global
LNOx nitrogen mass source and its uncertainty range is (5±3) Tg a−1
in this study. In spite of a smaller global flash rate, the best
estimate is essentially the same as in some earlier reviews, implying larger
flash-specific NOx emissions. The paper estimates the LNOx
accuracy required for various applications and lays out strategies for
improving estimates in the future. An accuracy of about 1 Tg a−1 or
20%, as necessary in particular for understanding tropical tropospheric
chemistry, is still a challenging goal. |
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