Long-term changes in the solar photosphere associated with changes in the coronal source flux

Foste, S. and Lockwood, M. ORCID: https://orcid.org/0000-0002-7397-2172 (2001) Long-term changes in the solar photosphere associated with changes in the coronal source flux. Geophysical Research Letters, 28 (8). pp. 1443-1446. ISSN 0094-8276 doi: 10.1029/2000GL011995

Abstract/Summary

Using sunspot observations from Greenwich and Mount Wilson, we show that the latitudinal spread of sunspot groups has increased since 1874, in a manner that closely mirrors the long-term (similar to 100 year) changes in the coronal source flux, F-s, as inferred from geomagnetic activity. This latitude spread is shown to be well correlated with the flux emergence rate required by the model of the coronal source flux variation by Solanki er al. [2000]. The time constant for the decay of this open flux is found to be 3.6 +/-0.8 years. Using this value, and quantifying the photospheric flux emergence rate using the latitudinal spread of sunspot groups, the model reproduces the observed coronal source flux variation. The ratio of the 100-year drift to the solar cycle amplitude for the flux emergence rate is found to be half of the same ratio for F-s.

Additional Information	First published online 2012
Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/38723
Identification Number/DOI	10.1029/2000GL011995
Refereed	Yes
Divisions	No Reading authors. Back catalogue items Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Additional Information	First published online 2012
Publisher	American Geophysical Union
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