Sunspot update for September 2017

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On Sunday NOAA posted its monthly update of the solar cycle, covering sunspot activity for September. That graph is posted below, with annotations.

September 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.

Last month saw the strongest amount of sunspot activity in a year, thus helping to bring the pace in the decline of sunspot activity back towards the low prediction from April 2007. This also suggests that the ramp down to solar minimum will continue through 2019, with minimum not occurring before then, at the earliest. At the same time, the increase in sunspot activity seen in September seems to have eased in October, with the return of a blank Sun this past week.



  • LocalFluff

    The level doesn’t seem to wanna die off to zero for years, as it did last time around 2009. Maybe a higher bottom comes together with lower highs. A more stable Sun surface.

  • Phill O

    We need to live a lot longer to see the true trends! What long term cycles the sun exhibits is an unknown. One could say a “known unknown”. What “unknown unknowns” are there for solar dynamics? If the number of scientist that worked on the CO2 model had of worked on the solar power climate change model, who knows what we would have discovered?

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