Do sunspots change the tempeature of the sun, if so,why and how?
Very good question! Yes, but the exact process is not completely understood yet. The magnetic field of sunspots inhibits energy transport from the interior of the Sun. Sunspots are therefore cooler, and consequently darker. The Sun gets a little darker when there is a big sunspot (up to 0.1%). One would therefore expect that during activity maximum, when there are many sunspots, the Sun is a little darker. But the opposite is true! The Sun actually is a little brighter during activity maximum (also about 0.1%). See http://www.pmodwrc.ch/tsi/composite/pics/comp_d25_05_0301.png for a plot of the total solar irradiance over the last 24 years. The sharp “needles” are sunspots crossing the disk. Dr.
