Please consider donating to Behind the Black, by giving either a one-time contribution or a regular subscription, as outlined in the tip jar below. 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.
Regular readers can support Behind The Black with a contribution via paypal:
If Paypal doesn't work for you, you can support Behind The Black directly by sending your donation by check, payable to Robert Zimmerman, to
Behind The Black
c/o Robert Zimmerman
Cortaro, AZ 85652
On Sunday NOAA posted its monthly update of the solar cycle, covering sunspot activity for September. That graph is posted below, with annotations.
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.