How does the surface of the photosphere conduct thermal energy from the convective zone to the corona, while remaining at such a relatively low temperature itself?
It seems odd to me that the photosphere is wedged between the convective zone and the corona, both of which are millions of degrees in temperature, while the photosphere itself is observed to be much colder by comparison - approx. 5-10 thousand degrees.
Based on my understanding of convection, this would require thermal energy to jump from the convective zone directly to the corona, and somehow skip the photosphere surface material in-between.
Is there a different model of convection that explains this?
Or is there a type of matter with thermal conductive properties that could accomplish this?
EDIT: Perhaps the convective zone is emitting heat as a different form of energy, such as electromagnetic - thereby allowing the outer layers to cool and sink in standard convection, but without directly heating up the surface of the photosphere.
Based on my understanding of the standard model of the sun, the following layers should be present:
Predicted:
- The core
A central area with pressures high enough to induce hot fusion of atomic nuclei - The radiative zone
A spinning ball of somewhat solid material surrounding the core, through which energy is conducted via radiation
Semi-observable:
- The convective zone
A layer of plasma surrounding the radiative zone, through which energy is conducted thermally via convection flows - millions of degrees in temperature
This is the subject of some 2012 studies by NASA in coordination with various other reputable institutions, which observed that the sun's convection appears to be "anomalously weak"
http://arxiv.org/pdf/1206.3173.pdf
Observable:
- The surface of the photosphere
The border between the convective zone and the corona - temperature in the ballpark of 5-10 thousand degrees - The corona
The outer plasma atmosphere, where flares take place - millions of degrees in temperature