Saturday, June 20, 2009

Oh where have all the sunspots gone? ***updated***

Shaun Saunders sends in an article from Science Daily that answers a question that has troubled astronomers for some time. For the past 2 years sunspots have been been a very rare event. The lack was at first difficult to lock down. Sunspot activity goes through an 11 year cycle and therefor the sun was already at a low activity point. But the decrease in activity was so deep and lasting for so long that there was speculation that the solar minimum might be entering a century long phase with virtually no activity that hasn't happened since the 17th century.

According to the article:
  • researchers announced that a jet stream deep inside the sun is migrating slower than usual through the star's interior, giving rise to the current lack of sunspots.
These jet streams (which in fact move 7 thousand miles below the surface of the sun) start at the poles and move down to the equator, which when reached, supports new sunspot activity, and a new jet stream is started at the pole. This migration takes 11 years or about 2 years per 10 degrees of angle. What has happened recently though is the migration is taking nearer 3 years to move down 10 degrees. The good news is that even though they are slower, the present jet stream will reach the equator which means there should be a return to normal solar activity.

Read the complete Science Digest article

Update: Tim sends in an update from Yahooo News.
It seems after a protracted absence of sun-spot activity, there has been a resurgence in the past week (July 2009) this after one of the longest period of no activity in modern history. Prior to this low point - scientist were looking for the next peak of activity in 2013 to be one of the most energetic, however after this quite period the next peak of solar flare activity is estimated to be very modest. This may turn out to be very good news indeed. Had the next high point been as bad as was being predicted, it is estimated that there could have been upwards of $2 trillion in initial damages by crippling communications on Earth, by damaging satellites in orbit and sensitive electronic equipment on the ground.

read the yahoo article here

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