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| Titel |
Effects of high-latitude thermosphere heating at various scale sizes simulated by a nonhydrostatic model |
| VerfasserIn |
Erdal Yigit, Aaron Ridley |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250036986
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| Zusammenfassung |
| For the first time, a nonhydrostatic coupled 3-D Global Ionosphere-Thermosphere Model has
been used at a very high spatial resolution of 2.5- longitude and 0.3125- latitude within
simulations of increasing resolution to investigate the variability of high-latitude Joule
and auroral heating. Even without the consideration of sub-grid scale electric field
variability, the high-latitude mean Joule and auroral heating intensify significantly
with increasing latitudinal resolution due mainly to resolving electric fields and
auroral precipitation. At ~ 370 km, the high-latitude mean resolved Joule heating
increases by more than 40% from 5-Ã 5- to 2.5-Ã 0.3125-. The associated increase
in auroral heating is ~20%. With increasing resolution, the high-latitude mean
ion and neutral temperatures increase by ~20 K in the thermosphere, while the
high-latitude mean electron density shows decreasing and increasing tendencies in
the upper thermosphere. Neutral winds intensify overall. In dark regions, electron
density depletions can decrease Joule heating locally, despite the increase in the
differential ion-neutral flow. At high spatial resolution, dynamical cooling associated with
enhanced neutral wind horizontal divergence is significant, which offsets the effects of
enhanced Joule heating, leading to the relatively small mean temperature increase. |
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