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| Titel |
Using cloud ice flux to parametrise large-scale lightning |
| VerfasserIn |
D. L. Finney, R. M. Doherty, O. Wild, H. Huntrieser, H. C. Pumphrey, A. M. Blyth |
| 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 ; 14, no. 23 ; Nr. 14, no. 23 (2014-12-02), S.12665-12682 |
| Datensatznummer |
250119202
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| Publikation (Nr.) |
 copernicus.org/acp-14-12665-2014.pdf |
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| Zusammenfassung |
| Lightning is an important natural source of nitrogen oxide
especially in the middle and upper troposphere. Hence, it is
essential to represent lightning in chemistry transport and coupled
chemistry–climate models. Using ERA-Interim meteorological
reanalysis data we compare the lightning flash density distributions
produced using several existing lightning parametrisations, as well
as a new parametrisation developed on the basis of upward cloud ice
flux at 440 hPa. The use of ice flux forms a link to the
non-inductive charging mechanism of thunderstorms. Spatial and
temporal distributions of lightning flash density are compared to
tropical and subtropical observations for 2007–2011 from the
Lightning Imaging Sensor (LIS) on the Tropical Rainfall Measuring Mission (TRMM) satellite. The well-used lightning flash parametrisation
based on cloud-top height has large biases but the derived annual
total flash density has a better spatial correlation with the LIS
observations than other existing parametrisations. A comparison of
flash density simulated by the different schemes shows that the
cloud-top height parametrisation has many more instances of moderate
flash densities and fewer low and high extremes compared to the
other parametrisations. Other studies in the literature have shown
that this feature of the cloud-top height parametrisation is in
contrast to lightning observations over certain regions. Our new ice
flux parametrisation shows a clear improvement over all the existing
parametrisations with lower root mean square errors (RMSEs) and better
spatial correlations with the observations for distributions of
annual total, and seasonal and interannual variations. The greatest
improvement with the new parametrisation is a more realistic
representation of the zonal distribution with a better balance
between tropical and subtropical lightning flash estimates. The new
parametrisation is appropriate for testing in chemistry transport
and chemistry–climate models that use a lightning parametrisation. |
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