In an eclipse, a red circle around the outside of the sun can sometimes can be seen. This is the chromosphere. Its red coloring is caused by the abundance of hydrogen. From the center of the sun to the chromosphere, the temperature decreases proportionally as the distance from the core increases. The chromosphere's temperature, however, is 7000 K, hotter than that of the photosphere.
Temperatures continue to increase through the corona.
Sunspots Sunspots are dark spots on the photosphere, typically with the same diameter as the Earth. They have cooler temperatures than the photosphere. The period of this solar cycle is about 11 years. The sun has enormous organized magnetic fields that reach from pole to pole. Loops of the magnetic field oppose convection in the convective envelope and stop the flow of energy to the surface.