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| Titel |
Long term changes in EUV and X-ray emissions from the solar corona and chromosphere as measured by the response of the Earth’s ionosphere during total solar eclipses from 1932 to 1999 |
| VerfasserIn |
C. J. Davis, E. M. Clarke, R. A. Bamford, M. Lockwood, S. A. Bell |
| 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 ; 19, no. 3 ; Nr. 19, no. 3, S.263-273 |
| Datensatznummer |
250014216
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| Publikation (Nr.) |
 copernicus.org/angeo-19-263-2001.pdf |
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| Zusammenfassung |
Measurements of the
ionospheric E region during total solar eclipses in the period 1932–1999 have
been used to investigate the fraction of Extreme Ultra Violet and soft X-ray
radiation, 8, that is emitted from the limb corona and chromosphere. The
relative apparent sizes of the Moon and the Sun are different for each eclipse,
and techniques are presented which correct the measurements and, therefore,
allow direct comparisons between different eclipses. The results show that the
fraction of ionising radiation emitted by the limb corona has a clear solar
cycle variation and that the underlying trend shows this fraction has been
increasing since 1932. Data from the SOHO spacecraft are used to study the
effects of short-term variability and it is shown that the observed long-term
rise in 8 has a negligible probability of being a chance occurrence.
Key words. Ionosphere (solar
radiation and cosmic ray effects) – Solar physics, astrophysics, and astronomy
(corona and transition region) |
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