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| Titel |
An estimate of the impact of transient luminous events on the atmospheric temperature |
| VerfasserIn |
E. Arnone, P. Berg, N. F. Arnold, B. Christiansen, P. Thejll |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7340
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| Digitales Dokument |
URL |
| Erschienen |
In: Solar, heliospheric and external geophysical effects on the Earth’s environment: scientific and educational initiatives ; Nr. 13 (2008-09-22), S.37-43 |
| Datensatznummer |
250011699
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| Publikation (Nr.) |
 copernicus.org/adgeo-13-37-2008.pdf |
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| Zusammenfassung |
| We present an order of magnitude estimate of the impact of sprites and other
transient luminous events (TLEs) on the atmospheric temperature via ozone
changes. To address the effects of expected TLE-ozone changes of at most a
few percent, we first study the linearity of the radiatively driven response
of a stratosphere-mesosphere model and of a general circulation model (GCM)
to a range of uniform climatological ozone perturbations. The study is
limited to Northern Hemisphere winter conditions, when planetary wave
activity is high and the non linear stratosphere-troposphere coupling can
be strong. Throughout most of the middle atmosphere of both models, the
radiatively driven temperature response to uniform 5% to 20% ozone
perturbations shows a close-to linear relationship with the magnitude of
the perturbation. A mid-latitude stratopause ozone perturbation is then
imposed as an idealised experiment that mimics local temperature gradients
introduced by the latitudinal dependence of TLEs. An unrealistically high
20% magnitude is adopted for the regional ozone perturbation to obtain
statistical significance in the model response. The local linearity of the
radiatively driven response is used to infer a first order estimate of
TLE-induced temperature changes of the order of 0.015 K under typical
conditions, and less than a peak temperature change of 0.3 K at 60–70 km
height in coincidence of extraordinarily active TLE-producing thunderstorms
before horizontal mixing quickly occurs. In the latter case, dedicated
mesoscale modelling is needed to study the relevance of regional non linear
processes which are expected to impact these radiatively driven responses. |
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