The Sun has a maximum and no one notices

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On July 8 NOAA released its monthly update of the Sun’s sunspot cycle, covering the period of June 2013. As I do every month, this graph is posted below, with annotations to give it context.

After a brief period of renewed but weak activity during the last three months, the Sun’s sunspot production has once again plunged, dropping back to the levels generally seen for most of 2012.

As predicted by some solar scientists, the Sun seems to have produced a double-peaked maximum, though the second peak appears at this time to have been remarkably wimpy and brief. It is still possible, however, that this second peak is not over and that we might see another burst of renewed activity in the next month or so, based on the Sun’s past behavior during the ending stages of the previous solar maximum in 2001 and 2002. Nonetheless, from all appearances it looks like the Sun has shot its load and is in the process of winding down from a solar maximum peak that occurred back late 2011.

What is especially fascinating about this is that when that peak occurred in 2011, no one noticed!

June 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. As you can see, none of these predictions came very close to predicting what actually happened.

The graph also shows that the Sun’s most active month occurred in October 2011. Based on the Sun’s past and present behavior, it is now unlikely that it will return that level of activity, which means that the Sun’s maximum actually occurred two years ago, and has since been in the process of winding down toward its next minimum.

Yet, for the past two years the scientists at the Marshall Space Flight center — which includes the field’s most prominent solar researchers such as David Hathaway — have been consistently and repeatedly predicting that the solar maximum had not yet arrived. From month to month they have been predicting that the actual maximum would occur sometime in 2013. At first they favored early 2013. Later they favored late 2013. Finally last month they decided the maximum would occur in the middle of 2013, during the summer, a prediction they still hold to on their website.

I should also note that David Hathaway and these Marshall scientists were also the scientists who in April 2007 had predicted that this maximum would be very strong and active. They didn’t get that right either.

Last week, these same scientists also held a press teleconference during a solar science conference to talk about the maximum (and do some damage control in my opinion). The event did not get much press, and I was unfortunately unable to participate because of my trip to the Grand Canyon.

Of the two press stories I have seen, one focused on the claim by these scientists that we are not headed for a Grand Minimum, a period when the solar cycle disappears and the Sun no longer produces sunspots for decades at a time. This story isn’t very informative or useful. Its conclusions are based purely on the speculations of these particular scientists, whose ability to predict anything has been very poor, while ignoring completely the predictions of other solar scientists, who have stated that they think a Grand Minimum is definitely possible in the next decade.

The other story more correctly focused on the known facts, how this cycle has been very very weak, and how all evidence points to the likelihood that the next maximum will be even weaker. Other than that, we really don’t know what’s going to happen next.

What no one seems to notice is that the actual maximum occurred two years ago, not now in 2013. When that 2011 peak occurred, everyone expected the number of sunspots to continue to rise in the coming years, so no one considered the October 2011 peak to be anything more than a temporary burp on the way to full maximum. Instead, it was the maximum. Afterward, the Sun has been struggling along, producing sunspots but in much lower numbers.

Overall, these facts suggest strongly to me that the scientists predicting a Grand Minimum in the coming years have a better chance of being right. It might not happen, but if I had to make a bet right now I’d give them the better odds.



  • Robert, thank you for keeping this on the routine watch items. Interesting to see how the Sun behaves. Let’s continue to watch this and the average surface temperatures (satellite) of the Earth over the next few years. I believe we have seen a possible correlation in the recent plateau of Earth’s surface temperatures.

  • R. Cotour

    Why would you follow the activity of the sun, it has little to do with the temperature on the earth?

  • joe

    The sun has a much larger influence than carbon dioxide in regards to temperature on planet earth, carbon dioxide, if I am not mistaken has an 800 year lag time following temperature rise!

  • You are correct about the lag, but the lag time itself is not so precisely known. Climate scientists do know that the temperature rises and falls, after which the percentage of CO2 appears to rise or fall accordingly.

  • joe

    I have a hard time believing that people do not understand the influence of the sun on this planets temperatures with regards to distance, and solar output which is not constant.

  • Scott

    By analogy, if you are sitting in your living room during the winter, and it seems a bit too warm, do you check the thermostat for the furnace, or kick the dog out for farting too much and raising the room temperature?

  • Edward

    Good joke, R. Cotour. Who would ever think that the main source of heat for the solar system would have little to do with planetary temperature?

  • john fealy

    I would scold the dog not for temperature fluctuation within the house but rather the methane lag that seemingly overtakes my oxigen levels therein.

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