As the days go by, I frequently show details of active region magnetograms images and charts, and other data, for active regions I think may be suspect of initiating the radio events we study.
I started studying solar radio emission in 1966, I am not finished yet :)
The degree of activity frequently varies much from day to day and is a complex subject studied for many decades.
Lidia van Driel-Gesztelyi and Lucie May Green have published last month a "Living Review of Solar Physics" titled:
"Evolution of Active Regions" , 98 pages, including 17 pages of references, free to download at:
Section 6 studies the case of AR 7978, "...subjected to the most comprehensive analysis of any AR..." as it evolved over a 6 month period.
Appendix A is a very good summary of Sunspot classifications, including the McIntosh and Hale methods.
I leave you repeating their quote from a poem by Laszlo Detre :
“ A Solar Physicist’s Lament ....
It looks as if many a sunny day
Will pass along on its way
Before we solve it all... "
My ignorance is vast
Have a wonderful day
Solar Dynamics Observatory - Now and Daily - Images Movies
Solar Type Examples
Comparison of Cycles 23 and 24 sunspot and coronal mass ejection numbers
http://sidc.oma.be/cactus/ CACTUS page
Introductory Radio Astronomy references
My recent event posts by month:
Links to earlier posts by month: