We are now at 21 days with no sunspots, it will be interesting to see if we reach a spotless 30 day period and then perhaps a spotless month of December.
From the data provided by NOAA’s Space Weather Prediction Center (SWPC) you can see just how little magnetic field activity there has been. I’ve included it below with the latest available update from December 6th, 2008:
click for a larger image
What I find most interesting about the Geomagnetic Average Planetary Index graph above is what happened around October 2005. Notice the sharp drop in the magnetic index and the continuance at low levels. Read on for more.
This looks much like a “step function” that I see on GISS surface temperature graphs when a station has been relocated to a cooler measurement environment. In the case of the sun, it appears this indicates that something abruptly “switched off” in the inner workings of the solar dynamo. Note that in the prior months, the magnetic index was ramping up a bit with more activity, then it simply dropped and stayed mostly flat.
Currently the Ap magnetic index continues at a low level, and while the “smoothed” data from SWPC is not made available for 2008, I’ve added it with a dashed blue line, and the trend appears to be going down.
As many regular readers know, I’ve always pointed out the sharp drop in 2005 with the following extended period of low activity as an odd occurance. Our resident solar astronomer Leif Svalgaard disagrees with this. But I’d also like to point out that this was the time when global sea level as measured by the JASON satellite and reported by the University of Colorado began to lose its upward trend.
Source: University of Colorado, Boulder
Coincidence? Perhaps. But I think investigation is needed to determine if there is any mechanism that would explain or exclude this correlation.
(h/t Joe D’aleo