>>22286584>Sunspots and Coronal Holesin a plasma, both the dimensions and the voltages of the anode tufts depend on the current density at that location (near the anode).
the tufts appear and/or disappear, as needed, to maintain a certain required relationship between +ion and electron numbers in the total current.
this property of anode tuft plasmas was discovered, quantified, and reported by Irving Langmuir over fifty years ago.
in the ES model, as with any plasma discharge, tufting disappears wherever the flux of incoming electrons impinging onto a given area of the Sun's surface is not sufficiently strong to require the shielding produced by the plasma double layer.
at any such location, the anode tufting collapses and we can see down to the actual anode surface of the Sun.
since there is no arc discharge occurring in these locations, they appear darker than the surrounding area and are termed "sunspots".
Of course, if a tremendous amount of energy were being produced in the Sun's interior, the spot should be brighter and hotter than the surrounding photosphere.
the fact that sunspots are dark and cool strongly supports the contention that very little, if anything, is going on in the Sun's interior. The center of the spot is called its umbra.
