Published in Physics World, 18 Jun 2009
The unusually long quiet period of the Sun’s present activity may be due to the motion of “sluggish” jet streams beneath the solar surface, according to scientists at the National Solar Observatory (NSO) in Arizona, US.
The scientists’ observations, which show an east–west jet stream has taken a year longer to migrate south by 10° than in the previous solar cycle, also indicate that the sun is moving into its next cycle.
“We need to continue these observations for many, many more years to fully understand what is going on,” said NSO researcher Frank Hill yesterday at a meeting of the solar-physics division of the American Astronomical Society in Boulder, Colorado, adding: “We cannot at this point definitively say [the jet stream] is a real cause, but I think it is quite clear that it is associated.” […]
The rest of this article is available here.