The sun's surface temperature is about 5800 K.

The sun's atmosphere (the corona) however is over 1000000 K.

 

How does the corona stay so hot?

 

I read the wikipedia article that I linked to, and that suggests that magnetic field of the sun heats the corona.

In addition, the sun spots seem to occur from the sun's interior.

Finally, "coronal loops" are very common in the corona (they're the "basic structure" according to wikipedia). It also mentions that (part of) the corona is always moving away from the sun due to the magnetic fluxes generating the solar wind.

 

In addition to the magnetic field that heats the corona, could it be that the corona is also heated by a constant flux of actual matter (atoms) that come from the interior of the sun to the corona. Gases cool down, and fall back into the sun where they can be heated again?

 

Is there a link between the high temperature of the sun's corona and the high temperature of our own ionosphere, which is also warmer than the surface of the earth?

 

Just some questions from a chemical engineer about stuff that we typically never have to think about. Friday afternoon brain fitness.

AFAIK the mystery of the high temperature of the corona is as-yet unresolved (fully).

 

http://www-spof.gsfc.nasa.gov/Education/wcorona.html

http://sunearthday.nasa.gov/2008/TTT/58_hotcorona.php

http://www.isas.ac.jp/e/forefront/2009/katsukawa/index.shtml

If the sun were to possess a positive core devoid of electrons, stellar fusion within the core might convert a positron to energy without annihilating any electron as part of the deal. Such action could be considered a virtual generation of an electron for the universe. Such events could explain the neutrino shortage that disturbs some scientists. Such a trend would give rise to an electron into any outer shell of electrons that might surround the sun, bringing consequential shifting of most electrons in such a shell as electrons strive for equidistance throughout such a stratum. We might expect such a shell full of wiggling electrons to heat up. Such an effect would toast the thin stream of gass passing through, hence raising coronal temperature.

If the sun were to possess a positive core devoid of electrons, stellar fusion within the core might convert a positron to energy without annihilating any electron as part of the deal. Such action could be considered a virtual generation of an electron for the universe. Such events could explain the neutrino shortage that disturbs some scientists. Such a trend would give rise to an electron into any outer shell of electrons that might surround the sun, bringing consequential shifting of most electrons in such a shell as electrons strive for equidistance throughout such a stratum. We might expect such a shell full of wiggling electrons to heat up. Such an effect would toast the thin stream of gass passing through, hence raising coronal temperature.

 

Even though this is an unresolved question in physics, that does not mean this is an invitation to speculation which has no support from accepted physics

 

The neutrino "shortage" has been addressed with the discovery of neutrino oscillations.

http://en.wikipedia.org/wiki/Neutrino_oscillation