Sunspot update for May 2017

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Last week NOAA posted its monthly update of the solar cycle, covering sunspot activity for May. Unfortunately, there appeared to be a problem with their posting software. Though the date of the image changed, the graph itself was not updated. I contacted NOAA, and Ann Newman, IT Specialist at NOAA’s
Space Weather Prediction Center, took a look and quickly fixed the problem.

The corrected graph is posted below, with annotations, as I have done now every month since 2010.

May 2017 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.

The decline in sunspot activity resumed in May, putting the trend back below the 2007 low prediction. Overall, the trend continues to suggest that this very weak solar maximum will end much earlier than predicted, and will make it an unprecedented short but weak cycle. As the Sun is at this moment blank, and has been for several days, I expect that June will end up with low numbers as well, continuing this trend.

As I have repeatedly said now monthly for six years, if history is any guide, the Sun’s low activity should correspond with cooler temperatures here on Earth. Why this happens is not yet understood, though there are theories.



  • Garry

    I came across this in-depth article on sunspot counts.

    I recognized (at least some of) the leaps in logic, so I don’t trust it entirely, but I was wondering if the parameters cited and their stated relationships are considered established.

  • Garry: The author of that article is a good researcher, and a intelligent skeptic. All he is doing is outlining in great detail all the facts that solar scientists have been recognizing for the past decade that suggest that solar activity is presently on a downward trend.

    None of this does a good job at predicting the future, however, since we really do not yet understand the underlying causes of the Sun’s fluctuations.

  • Garry

    Thanks; what turned me off in that article was the line “therefore, continuing cooling is in store”; that seems too definitive a statement to me.

    I had never encountered some of the parameters he discusses, and wondered whether he was overreaching/overanalyzing

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