Decline to solar minimum continues

Please consider donating to Behind the Black, by giving either a one-time contribution or a regular subscription, as outlined in the tip jar to the right. Your support will allow me to continue covering science and culture as I have for the past twenty years, independent and free from any outside influence.

It’s that time again buckos! On Monday NOAA posted its monthly update of the solar cycle, showing the Sun’s sunspot activity in October. As I have done every month since 2010, I am posting it here, with annotations to give it context.

The decline in sunspot continue steadily, matching the red prediction curve except that, as it has for this entire solar maximum, the number of sunspots continues to be less than expected. Not only did the ramp up start later and not quite reach the levels predicted, the ramp down started early. Overall, this now ending solar maximum is the weakest in a century. The big question remains: Is the Sun about to head into its first Grand Minimum since the 1600s, or is this weak maximum a one-time event to be followed by stronger activity in later cycles.

No matter what anyone tells you, no one knows.

October 2015 Solar Cycle graph

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.


  • Phill O

    As far as predictions go, there was a precursor (believed) which indicated that this cycle was going to be low. The same precursor indicated the next cycle would be lower still. However, until observations confirm the predictions, then we really do not know if this precursor is real. Hopefully, I will be around for the next two cycles to observe such a grand minimum and be able to tell the CO2 model folk they were wrong.

    Yesterday we were out to the Chester Lake and Burstall pass trailheads (Kananaskis Country) and the snow banks have been pushed back and chopped off already. This seems rather early for this area. The ski hills have opened early this year also. We have seen rather large snow falls for the last 4 or so years at the ski hills. With el nino high, some are predicting a low snow fall year for the Canadian Rockies. We will see!

  • wodun

    Thanks for keeping track of this. If it wasn’t for you, those past predictions would have disappeared. It is an exciting time, a golden age of scientific discovery, but arrogance and hubris are traits that belong to all humans and it is good to be reminded that we still don’t know as much as we think we do about how natural processes work.

Leave a Reply

Your email address will not be published. Required fields are marked *