Russ Steele
For a few weeks it looked like Solar Cycle 24 was well underway. Now the sunspots have sputtered to a stop, with 10 days of no spots. Could we be on the cusp of another Grand Minimum? (Click graphic for larger image)
Ken Tapping writing at the National Research Council of Canada’s web site:
What is just as intriguing is that around the time of the Maunder Minimum the Earth's climate cooled, to the point where the River Thames in London froze over. This does not normally happen. At the beginning of the 19th Century the Sun went through another period of low activity, although not as low as happened in the Maunder Minimum. At that time there was another cooling of the climate. We now know that when the Sun is more active, producing more sunspots and other forms of activity, it also gets brighter, and when that activity falls, it gets dimmer. This is the Sun's contribution to changing climate, and one reason we keep a close eye on it.
The last solar maximum was in 2000-2002. Then the activity declined to the next minimum, and then stayed there. Some suggested another Maunder or Dalton Minimum was starting. However, early this year the next activity cycle started. On the other hand it's not clear we're out of the woods yet, because this new cycle is different. The relationships between activities in different parts of the Sun have changed, and the sunspots have weaker magnetic fields than they used to.
Many other stars show activity cycles, just like the Sun's; others do not. Maybe these stars are taking some time off, the way the Sun does. Calculations by a friend at the University of Montréal show activity cycles can stop and restart, and another at the NRC Institute for Information Technology has found that subtle changes in the rhythm of solar activity are fairly common. The cycles are not simple oscillations, like the movement of a swing. Today, with our technologies and environment under increased pressure, understanding and monitoring solar behaviour is critically important.
Full article is here.
Cross posted at Dalton Minimum Returns.
