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Titel |
Substorm-related thermospheric density and wind disturbances derived from CHAMP observations |
VerfasserIn |
P. Ritter, H. Lühr, E. Doornbos |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
0992-7689
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Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 28, no. 6 ; Nr. 28, no. 6 (2010-06-01), S.1207-1220 |
Datensatznummer |
250016838
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Publikation (Nr.) |
copernicus.org/angeo-28-1207-2010.pdf |
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Zusammenfassung |
The input of energy and momentum from the magnetosphere is most efficiently
coupled into the high latitude ionosphere-thermosphere. The phenomenon we are
focusing on here is the magnetospheric substorm. This paper presents substorm
related observations of the thermosphere derived from the CHAMP satellite.
With its sensitive accelerometer the satellite can measure the air density
and zonal winds. Based on a large number of substorm events the average high
and low latitude thermospheric response to substorm onsets was deduced.
During magnetic substorms the thermospheric density is enhanced first at high
latitudes. Then the disturbance travels at an average speed of 650 m/s to
lower latitudes, and 3–4 h later the bulge reaches the equator on the
night side. Under the influence of the Coriolis force the travelling
atmospheric disturbance (TAD) is deflected westward. In accordance with
present-day atmospheric models the disturbance zonal wind velocities during
substorms are close to zero near the equator before midnight and attain
moderate westward velocities after midnight. In general, the wind system is
only weakly perturbed (Δvy<20 m/s) by substorms. |
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