Much fanfare was associated with the reappearance of sunspots earlier this year, marking the beginning of a new period of high solar activity. Now come a number of reports saying the Sun is most likely headed for a prolonged period of low activity, possibly rivaling the Maunder minimum. Three independent studies of the Sun's dynamics all predict that the next solar cycle will be significantly delayed and might even be skipped. The Maunder minimum is associated with a prolonged period of climate cooling known as the Little Ice Age. Whether Earth's climate is headed for a significant cooling trend has become a matter of heated debate, while at the same time NASA is warning that a quite Sun can also be a deadly Sun. In the 1850s, following a period of low sunspot activity, the largest coronal ejection event ever witnessed caused havoc with telegraphs and ship's compasses around the world. Such an ejection today could cause widespread power outages and failure of electronic equipment. Will our star turn both quiet and deadly?
Sunspots are relatively cool, dark blemishes on the Sun's surface that indicate regions of intense magnetic activity. Some sunspots are gigantic, often wider than Earth with magnetic fields reaching far into space. For centuries scientists have been using sunspots to gauge solar activity, discovering that visible activity waxes and wains in a regular 11 year cycle. After an unusually quiet period
we are now in Solar Cycle 24, which should peak sometime in 2013. But it is what solar scientists are predicting to come after SC 24 that is causing concern among climate scientists.
Newly reported solar observations, including fading sunspots and weakening magnetic activity near the poles, could be indications that the Sun could be less active in the coming years. Three independent studies by solar experts all predict that the next solar cycle may not happen, or at least be significantly delayed. Astrogeophysicist Frank Hill and colleagues at the National Solar Observatory, have been monitoring solar cycles using a technique called helioseismology. Hill was the lead author on the first of three papers
on these results presented at the American Astronomical Society conference in New Mexico. Using data from the Global Oscillation Network Group (GONG) of six observing stations around the world, the team translates surface pulsations caused by sound reverberating through the Sun into models of its internal structure.