Accessibility navigation


Long-term variations in the magnetic field of the Sun and possible implications for terrestrial climate

Lockwood, M. and Foster, S.S. (2000) Long-term variations in the magnetic field of the Sun and possible implications for terrestrial climate. In: Proc. 1st. Solar and Space Weather Euroconference, 25-29 September 2000, St Cruz de Tenerife, Tenerofe, Spain, pp. 85-94. (“The solar cycle and Terrestrial Climate”, Proc. 1st. Solar and Space Weather Euroconference, ESP SP-463)

Full text not archived in this repository.

Abstract/Summary

Recent studies of the variation of geomagnetic activity over the past 140 years have quantified the "coronal source" or "open" magnetic flux F-s that leaves the solar atmosphere and enters the heliosphere and have shown that it has risen, on average, by 34% since 1963 and by 140% since 1900. This variation is reflected in studies of the heliospheric field using isotopes deposited in ice sheets and meteorites by the action of galactic comic rays. The variation has also been reproduced using a model that demonstrates how the open flux accumulates and decays, depending on the rate of flux emergence in active regions and on the length of the solar cycle. The cosmic ray flux at energies > 3 GeV is found to have decayed by about 15% during the 20(th) century (and by about 4% at > 13 GeV). We show that the changes in the open flux do reflect changes in the photospheric and sub-surface field which offers an explanation of why open flux appears to be a good proxy for solar irradiance extrapolation. Correlations between F-s, solar cycle length, L, and 11-year smoothed sunspot number, R-11, explain why the various irradiance reconstructions for the last 150 years are similar in form. Possible implications of the inferred changes in cosmic ray flux and irradiance for global temperatures on Earth are discussed.

Item Type:Conference or Workshop Item (Paper)
Refereed:Yes
Divisions:No Reading authors. Back catalogue items
Faculty of Science > School of Mathematical, Physical and Computational Sciences > Department of Mathematics and Statistics
Faculty of Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
ID Code:38726
Publisher Statement:PROCEEDINGS OF THE 1ST SOLAR AND SPACE WEATHER EUROCONFERENCE ON THE SOLAR CYCLE AND TERRESTRIAL CLIMATE Published by European Space Agency Book Series: ESA SPECIAL PUBLICATIONS Volume: 463 ESA SP-463

University Staff: Request a correction | Centaur Editors: Update this record

Page navigation