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| Titel |
Estimates of lightning NOx production from GOME satellite observations |
| VerfasserIn |
K. F. Boersma, H. J. Eskes, E. W. Meijer, H. M. Kelder |
| 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 ; 5, no. 9 ; Nr. 5, no. 9 (2005-09-01), S.2311-2331 |
| Datensatznummer |
250003059
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| Publikation (Nr.) |
 copernicus.org/acp-5-2311-2005.pdf |
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| Zusammenfassung |
| Tropospheric NO2 column retrievals from the Global Ozone Monitoring
Experiment (GOME) satellite spectrometer are used to quantify the source
strength and 3-D distribution of lightning produced nitrogen oxides
(NOx=NO+NO2). A sharp increase of NO2 is
observed at convective cloud tops with increasing cloud top height,
consistent with a power-law behaviour with power 5±2. Convective
production of clouds with the same cloud height are found to produce
NO2 with a ratio 1.6/1 for continents compared to oceans. This
relation between cloud properties and NO2 is used to construct a
10:30 local time global lightning NO2 production map for 1997. An
extensive statistical comparison is conducted to investigate the capability
of the TM3 chemistry transport model to reproduce observed patterns of
lightning NO2 in time and space. This comparison uses the averaging
kernel to relate modelled profiles of NO2 to observed NO2
columns. It exploits a masking scheme to minimise the interference of other
NOx sources on the observed total columns. Simulations are performed
with two lightning parameterizations, one relating convective preciptation
(CP scheme) to lightning flash distributions, and the other relating the
fifth power of the cloud top height (H5 scheme) to lightning distributions.
The satellite-retrieved NO2 fields show significant correlations with
the simulated lightning contribution to the NO2 concentrations for
both parameterizations. Over tropical continents modelled lightning
NO2 shows remarkable quantitative agreement with observations. Over
the oceans however, the two model lightning parameterizations overestimate
the retrieved NO2 attributed to lightning. Possible explanations for
these overestimations are discussed. The ratio between satellite-retrieved
NO2 and modelled lightning NO2 is used to rescale the
original modelled lightning NOx production. Eight estimates of the
lightning NOx production in 1997 are obtained from spatial and
temporal correlation methods, from cloud-free and cloud-covered observations,
and from two different lightning parameterizations. Accounting for a wide
variety of random and possible systematic errors, we estimate the global
NOx production from lightning to be in the range 1.1–6.4 Tg N
in 1997. |
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