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| Titel |
A critical note on the IAGA-endorsed Polar Cap index procedure: effects of solar wind sector structure and reverse polar convection |
| VerfasserIn |
P. Stauning |
| 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 ; 33, no. 11 ; Nr. 33, no. 11 (2015-11-30), S.1443-1455 |
| Datensatznummer |
250121272
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| Publikation (Nr.) |
 copernicus.org/angeo-33-1443-2015.pdf |
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| Zusammenfassung |
| The International Association of Geomagnetism and Aeronomy (IAGA) has
recently endorsed a new Polar Cap (PC) index version to supersede
the previous seven different versions of the PCN (North) index and the five
different PCS (South) index versions. However, the new PC index has some
adverse features which should be known and taken into account by users of
the index. It uses in its derivation procedure an "effective" quiet day
level (QDC) composed of a "basic" QDC and an added solar wind sector term
related to the azimuthal component (By) of the interplanetary magnetic field (IMF).
The added IMF By-related terms may introduce unjustified
contributions to the PC index of more than 2 index units (mV m−1).
Furthermore, cases of reverse convection during strong northward IMF Bz (NBZ)
conditions included in the database for calculation of index
coefficients can cause unjustified index enhancements of 0.5–1 mV m−1 during
calm conditions, reduction of index values by more than 20 % during
disturbed conditions, and inconsistencies between index coefficients and
index values for the northern and southern polar caps. The aim here is to
specify these adverse features and quantify their effects, and to suggest
alternative steps for future modifications of the index procedure. |
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