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| Titel |
Modeling the plasma chemistry of stratospheric Blue Jet streamers |
| VerfasserIn |
Holger Winkler, Justus Notholt |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250091422
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| Publikation (Nr.) |
 EGU/EGU2014-5715.pdf |
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| Zusammenfassung |
| Stratospheric Blue Jets (SBJs) are upward propagating discharges in the altitude range
15–40km above thunderstorms. The currently most accepted theory associates SBJs to the
development of the streamer zone of a leader. The streamers emitted from the leader can
travel for a few tens of kilometers predominantly in the vertical direction (Raizer et al.,
2007). The strong electric fields at the streamer tips cause ionisation, dissociation, and
excitation, and give rise to chemical perturbations. While in recent years the effects of electric
discharges occurring in the mesosphere (sprites) have been investigated in a number of model
studies, there are only a few studies on the impact of SBJs. However, chemical
perturbations due to SBJs are of interest as they might influence the stratospheric ozone
layer.
We present results of detailed plasma chemistry simulations of SBJ streamers for both
day-time and night-time conditions. Any effects of the subsequent leader are not considered.
The model accounts for more than 500 reactions and calculates the evolution of the 88
species under the influence of the breakdown electric fields at the streamer tip. As the SBJ
dynamics is outside the scope of this study, the streamer parameters are prescribed. For this
purpose, electric field parameters based on Raizer et al. (2007) are used. The model is
applied to the typical SBJ altitude range 15–40 km. The simulations indicate that SBJ
streamers cause significant chemical perturbations. In particular, the liberation of
atomic oxygen during the discharge leads to a formation of ozone. At the same time,
reactive nitrogen and hydrogen radicals are produced which will cause catalytic ozone
destruction.
Reference:
Raizer et al. (2007), J. Atmos. Solar-Terr. Phys., 69 (8), 925–938. |
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