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| Titel |
Study of the solar wind coupling to the time difference horizontal geomagnetic field |
| VerfasserIn |
P. Wintoft |
| 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.1949-1957 |
| Datensatznummer |
250015279
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| Publikation (Nr.) |
 copernicus.org/angeo-23-1949-2005.pdf |
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| Zusammenfassung |
| The local ground geomagnetic field fluctuations (Δ B) are dominated by
high frequencies and 83% of the power is located at periods of 32 min or
less. By forming 10-min root-mean-square (RMS) of Δ B a major part
of this variation is captured. Using measured geomagnetic induced currents
(GIC), from a power grid transformer in Southern Sweden, it is shown that the
10-min standard deviation GIC may be computed from a linear model using the
RMS Δ X and Δ Y at Brorfelde (BFE: 11.67° E,
55.63° N), Denmark, and Uppsala (UPS: 17.35° E,
59.90° N), Sweden, with a correlation of 0.926±0.015. From
recurrent neural network models, that are driven by solar wind data, it is
shown that the log RMS Δ X and Δ Y at the two locations may be
predicted up to 30 min in advance with a correlation close to 0.8:
0.78±0.02 for both directions at BFE; 0.81±0.02 and 0.80±0.02 in
the X- and Y-directions, respectively, at UPS. The most important inputs
to the models are the 10-min averages of the solar wind magnetic field
component Bz and velocity V, and the 10-min standard deviation
of the proton number density σn. The average proton
number density n has no influence.
Keywords. Magnetospheric physics (Solar wind - magnetosphere
interactions) – Geomagnetism and paleomagnetism
(Rapid time variations) |
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