 |
| Titel |
Lightning NOx emissions over the USA constrained by TES ozone observations and the GEOS-Chem model |
| VerfasserIn |
L. Jourdain, S. S. Kulawik, H. M. Worden, K. E. Pickering, J. Worden, A. M. Thompson |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 1 ; Nr. 10, no. 1 (2010-01-08), S.107-119 |
| Datensatznummer |
250007895
|
| Publikation (Nr.) |
 copernicus.org/acp-10-107-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| Improved estimates of NOx from lightning sources are required to
understand tropospheric NOx and ozone distributions, the oxidising
capacity of the troposphere and corresponding feedbacks between chemistry
and climate change. In this paper, we report new satellite ozone
observations from the Tropospheric Emission Spectrometer (TES) instrument
that can be used to test and constrain the parameterization of the lightning
source of NOx in global models. Using the National Lightning Detection
(NLDN) and the Long Range Lightning Detection Network (LRLDN) data as well
as the HYPSLIT transport and dispersion model, we show that TES provides
direct observations of ozone enhanced layers downwind of convective events
over the USA in July 2006. We find that the GEOS-Chem global
chemistry-transport model with a parameterization based on cloud top height,
scaled regionally and monthly to OTD/LIS (Optical Transient Detector/Lightning
Imaging Sensor) climatology, captures the ozone enhancements seen
by TES. We show that the model's ability to reproduce the location of the
enhancements is due to the fact that this model reproduces the pattern of
the convective events occurrence on a daily basis during the summer of 2006
over the USA, even though it does not well represent the relative
distribution of lightning intensities. However, this model with a value of 6 Tg N/yr
for the lightning source (i.e.: with a mean production of 260 moles
NO/Flash over the USA in summer) underestimates the intensities of the ozone
enhancements seen by TES. By imposing a production of 520 moles NO/Flash for
lightning occurring in midlatitudes, which better agrees with the values
proposed by the most recent studies, we decrease the bias between TES and
GEOS-Chem ozone over the USA in July 2006 by 40%. However, our conclusion
on the strength of the lightning source of NOx is limited by the fact
that the contribution from the stratosphere is underestimated in the
GEOS-Chem simulations. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|