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Statistical properties of H alpha flares in relation to sunspots and active regions in the cycle 23

Zharkov, S.I.; Zharkova, V.V.

Authors

V.V. Zharkova



Abstract

The statistical properties of flare occurrences compared with those of sunspot and active region areas in the cycle 23. The flare numbers in the cycle 23 of all significances and locations were obtained from the Solar Geophysical Data (SGD) and the other data were taken from the automated Solar Feature Catalogues (SFC, http://solar.inf.brad.ac.uk). The average monthly flare occurrences during the whole cycle correlate closely with the total and cumulative areas of active regions and sunspots. The cumulative distribution of solar flare occurrences at different latitudes in the northern and southern hemispheres versus the time reveal a strong asymmetry with a domination of one or other hemispheres similar to the cumulative distributions of sunspots and active regions. Although the sunspot area asymmetry lags the flare occurrence asymmetry by about a few months at the ascending phase of the cycle and up to 12 months in the descending one. The latitudinal distribution of flare occurrences in the whole period reveals a well defined maximum at in the northern and two maxima at and in the southern hemisphere. The longitudinal distributions of flare occurrence residuals of the running values and those averaged with a one year filter reveal a set of persistent longitudes in the opposite hemispheres lasting for about 1.0–1.5 years and changing quickly a few times over the cycle phases.

Journal Article Type Article
Publication Date Feb 28, 2011
Journal JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS
Print ISSN 1364-6826
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 73
Issue 42796
Pages 264 - 270
APA6 Citation Zharkov, S., & Zharkova, V. (2011). Statistical properties of H alpha flares in relation to sunspots and active regions in the cycle 23. Journal of atmospheric and solar-terrestrial physics, 73(42796), 264 - 270. https://doi.org/10.1016/j.jastp.2009.11.010
DOI https://doi.org/10.1016/j.jastp.2009.11.010
Keywords Sun: magnetic field; Sun: active region; Sun: sunspots; Sun: flares; Sun: active latitudes; Sun: persistent longitude
Publisher URL https://www.sciencedirect.com/science/article/pii/S1364682609003022?via%3Dihub
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