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Titel |
Observations by the CUTLASS radar, HF Doppler, oblique ionospheric sounding, and TEC from GPS during a magnetic storm |
VerfasserIn |
D. V. Blagoveshchensky, Mark Lester, V. A. Kornienko, I. I. Shagimuratov, A. J. Stocker, E. M. Warrington |
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 ; 23, no. 5 ; Nr. 23, no. 5 (2005-07-28), S.1697-1709 |
Datensatznummer |
250015258
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Publikation (Nr.) |
copernicus.org/angeo-23-1697-2005.pdf |
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Zusammenfassung |
Multi-diagnostic observations, covering a significant area
of northwest Europe, were made during the magnetic storm interval (28–29
April 2001) that occurred during the High Rate SolarMax IGS/GPS-campaign. HF
radio observations were made with vertical sounders (St. Petersburg and
Sodankyla), oblique incidence sounders (OIS), on paths from Murmansk to
St. Petersburg, 1050 km, and Inskip to Leicester, 170 km, Doppler sounders,
on paths from Cyprus to St. Petersburg, 2800 km, and Murmansk to St. Petersburg,
and a coherent scatter radar (CUTLASS, Hankasalmi, Finland).
These, together with total electron content (TEC) measurements made at GPS
stations from the Euref network in northwest Europe, are presented in this
paper. A broad comparison of radio propagation data with ionospheric data at
high and mid latitudes, under quiet and disturbed conditions, was
undertaken. This analysis, together with a geophysical interpretation, allow
us to better understand the nature of the ionospheric processes which occur
during geomagnetic storms. The peculiarity of the storm was that it
comprised of three individual substorms, the first of which appears to have
been triggered by a compression of the magnetosphere. Besides the storm
effects, we have also studied substorm effects in the observations
separately, providing an improved understanding of the storm/substorm
relationship. The main results of the investigations are the following. A
narrow trough is formed some 10h after the storm onset in the TEC which is
most likely a result of enhanced ionospheric convection. An enhancement in
TEC some 2–3 h after the storm onset is most likely a result of heating
and upwelling of the auroral ionosphere caused by enhanced currents. The
so-called main effect on ionospheric propagation was observed at
mid-latitudes during the first two substorms, but only during the first
substorm at high latitudes. Ionospheric irregularities observed by CUTLASS
were clearly related to the gradient in TEC associated with the trough. The
oblique sounder and Doppler observations also demonstrate differences
between the mid-latitude and high-latitude paths during this particular
storm.
Keywords. Ionosphere (Ionospheric disturbances) – Magnetospheric
physics (Storms and substorms) – Radio science
(Ionospheric propagation) |
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