Centennial changes in the solar wind speed and in the open solar flux

Rouillard, A. P., Lockwood, M. ORCID: https://orcid.org/0000-0002-7397-2172 and Finch, I. (2007) Centennial changes in the solar wind speed and in the open solar flux. Journal of Geophysical Research, 112. A05103. ISSN 0148-0227 doi: 10.1029/2006JA012130

Abstract/Summary

We use combinations of geomagnetic indices, based on both variation range and hourly means, to derive the solar wind flow speed, the interplanetary magnetic field strength at 1 AU and the total open solar flux between 1895 and the present. We analyze the effects of the regression procedure and geomagnetic indices used by adopting four analysis methods. These give a mean interplanetary magnetic field strength increase of 45.1 ± 4.5% between 1903 and 1956, associated with a 14.4 ± 0.7% rise in the solar wind speed. We use averaging timescales of 1 and 2 days to allow for the difference between the magnetic fluxes threading the coronal source surface and the heliocentric sphere at 1 AU. The largest uncertainties originate from the choice of regression procedure: the average of all eight estimates of the rise in open solar flux is 73.0 ± 5.0%, but the best procedure, giving the narrowest and most symmetric distribution of fit residuals, yields 87.3 ± 3.9%.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/38542
Item Type	Article
Refereed	Yes
Divisions	No Reading authors. Back catalogue items Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Uncontrolled Keywords	open solar flux; solar wind; long-term change
Publisher	American Geophysical Union
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