Photosphere, Sunspots and Bright Points
It is absolutely not true that we would expect to see white light along the convection tube, under these circumstances, from deeper in the sun because the plasma is too opaque.
I said it this way, "under these circumstances", so I could lead into a related topic, which I will present here. Mozina assumes that the sun below the photosphere must be cooler than the photosphere, partly out of unreasonable preconception, and partly by seriously misinterpreting the images & physics of sunspots. As I have already shown extensively elsewhere, scientists can derive the temperature profile with depth of the photosphere, primarily through observations of the bright solar limb projected against the dark background of empty space (
Post 915 and links therein). This is enough by itself to refute Mozina's claims, but the high temperature of the subphotosphere is revealed in other ways as well.
Photospheric Bright Points
See
Astronomy Picture of the Day for April 16 2010 and the associated research paper
Magnetic bright points in the quiet sun; Sanchez Almeida,
et al., 2010, accepted for publication in Astrophysical Journal Letters. In a field of view 68.5 x 68.5 arcseconds the authors count 2380 bright points concentrated in the dark lanes of relatively cool downwelling plasma between the bright upwelling granular cores. These intergranular bright points were discovered in 1974 (
Mehltretter, 1974) and are thought to represent a significant fraction of the unresolved photospheric magnetic flux, where "unresolved" refers to magnetic structures of angular size below the spatial resolution capabilities of solar telescopes. The bright points are thought to represent the ends of spaghetti like magnetic structures that reach into the hotter subphotosphere. While the dark lane material around the points is downwelling, the material inside the magnetic filaments is upwelling, hot subphotosphere plasma, which explains why the bright points are bright.
We have known for quite a while that there are magnetic structures, supporting kilo-Gauss magnetic fields, that have not been spatially resolved (
Beckers, 1977;
Solanki, 1993). It has been assumed, because it makes perfectly good sense and is consistent with observations and plasma physics, that the bright points are magnetic structures, despite their being below the spatial resolution of photospheric magnetic field measurements (e.g.,
de Wijn, et al., 2008). Furthermore, recent higher spatial resolution photospheric magnetic field studies continue to correlate the bright points with still unresolved magnetic structures (e.g.,
Viticchie, et al., 2009). So the assumption that bright points represent magnetic structures that reach into the subphotosphere is not simply an arbitrary assumption, but rather an assumption based on a combination of increasingly high resolution observations of the solar photosphere and well known plasma physics.
So these bright points represent yet another line of evidence pointing to a subphotosphere that is hotter, not cooler, than the observed photosphere. This is also consistent with the independent derivation of the photospheric temperature profile based on solar limb observations.
Umbral Bright points
Bright points, much the same as those discussed above, are not relegated only to the dark lanes between photospheric granules. They also occur in the dark umbra and penumbra of sunspots (e.g.,
Prasad Choudhary & Shimizu, 2010). These bright points are also associated with small spatial scale magnetic fields and are also hotter than the surrounding material. There is no reason to believe that these bright points are any different than the bright points found in the quiet photosphere. These bright points are also windows into the deeper & hotter photosphere. Note that umbral bright points are consistently hotter with increasing distance from the center of the umbra, exactly what one would expect given the standard model of sunspots.
About the Photosphere
Let me briefly summarize the standard science of the solar photosphere. We derive a temperature profile with depth from limb observations and conclude that the temperature increases with depth, all the way to the limit of observability. This conclusion is supported by independent observations of bright points in the quiet solar photosphere, as well as the umbrae & penumbrae of sunspots. This conclusion is further supported by simple, ordinary physics; if you compress something, it heats up. The subphotosphere must be warmer than the photosphere because it has all the weight of the photosphere pressing down on it. Hence, even if the sun had no internal heat source, it would still be required by physics that the subphotosphere be hotter, not cooler. However, if we add the obvious internal heat source by nuclear fusion (or any other internal mechanism), then once again the outflow of energy from the deep interior requires that the subphotosphere be hotter, not cooler. Against this impressive array of scientific evidence, Mr. Mozina offers no science or physics based argument of any kind; rather, he has only his subjective & biased interpretation of qualitative (non-numeric) image data to offer. I think there can be no doubt at this point but that the Mozina argument concerning the nature of the solar photosphere is as completely refuted as an argument can be.
