Solar Activity

I was discussing solar activity with one of my brothers this past week.  There are so many parts and effects here: the observed eleven year cycle, the problems with predicting what will be going on in the next cycle, how it all affects radio wave propagation, how long we've been seriously observing the sun, etc.  Toward the end of the discussion I mentioned this page on solar physics from NASA.  Now that I've posted the link here, there's not a lot else to say other than (a) click through, (b) it's a short read, (c) with some nice graphics (sample below), (d) near the bottom of the page there are links to two review papers if you really want to know more.  Enjoy!