Variable Sun

In an earlier academic life experience I did sun modeling. This field has made considerable strides over the years. I am no longer involved with the technologies at play, but it is clear that the models used do not predict. It has always been known that the sun, as all stars, is variable to some degree. We are getting more information now about how much. More on our most recent learning:

" ... SUNSPOTS come and go, but recently they have mostly gone. For centuries, astronomers have recorded when these dark blemishes on the solar surface emerge, only for them to fade away again after a few days, weeks or months. Thanks to their efforts, we know that sunspot numbers ebb and flow in cycles lasting about 11 years.

But for the past two years, the sunspots have mostly been missing. Their absence, the most prolonged for nearly a hundred years, has taken even seasoned sun watchers by surprise. "This is solar behaviour we haven't seen in living memory," says David Hathaway, a physicist at NASA's Marshall Space Flight Center in Huntsville, Alabama.... "