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Letter: Jupiter's influence

Published 20 March 2004

From Glyn Wainwright

While the work of Mausumi Dikpati suggests that meridional flows in the sun’s convective layer may allow us to forecast sunspot activity (6 March, p 38), other forces may also be at work. In particular, the giant planets in the solar system may play a role through the gravitational pull they exert on the massive amount of fluid flowing in the outer layer of the sun.

Curiously, this gravitational force can be expressed as a Fourier series whose most important terms have interesting periodicities: one of these coincides with the 11-year cycle of the sunspots. What we may be seeing, therefore, is the direct influence of planetary tidal forces and their effects on the stability of the magnetic loops created in the meridional flows in the sun’s convective layer. These forces could be a major factor in the cycle of magnetic loops believed to create the sunspots.

Jupiter is the largest contributor to the solar plasma tides. It may eventually transpire that its influence contributes to our climate.

Leeds, UK

Issue no. 2439 published 20 March 2004

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