The chemistry of daytime sprite streamers – a model study
The chemical processes in daytime sprite streamers in the altitude range of 30–54 km are investigated by means of a detailed ion–neutral chemistry model (without consideration of transport). The focus lies on nitrogen, hydrogen and oxygen species, and in particular on ozone perturbations. Initial ef...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-04-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/14/3545/2014/acp-14-3545-2014.pdf |
| Summary: | The chemical processes in daytime sprite streamers in the altitude range of
30–54 km are investigated by means of a detailed ion–neutral chemistry
model (without consideration of transport).
The focus lies on nitrogen, hydrogen and oxygen species, and in
particular on ozone perturbations.
Initial effects of the breakdown electric fields at the tip of
sprite streamers include a short-term loss of ozone due to ion–chemical
reactions, a production of nitrogen radicals, and a liberation of
atomic oxygen. The latter leads to a formation of ozone.
In terms of relative ozone change, this effect decreases with altitude.
The model results indicate that the subsequent ozone perturbations due
to daytime sprites streamers differ considerably from the ones of
night-time events.
For night-time conditions, reactive nitrogen produced at the streamer
heads is rapidly converted into significantly less
reactive NO<sub>2</sub>, and there is basically no ozone depletion. The
situation is different for daytime conditions where NO<sub>x</sub> causes
catalytic ozone destruction. As a consequence, there is significant
ozone loss in sprite streamers in the daytime atmosphere, in
particular at higher altitudes. At an altitude of 54 km, ozone
in the streamer column has decreased by about 15% fifteen minutes
after the sprite event. |
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| ISSN: | 1680-7316 1680-7324 |