It's called science. Why is the sun's atmosphere hotter than it's surface? Let's try and figure it out.
It can't be science, not even guessing.
A 2 million degree temperature of the Sun's corona was invented ad-hoc in order to avoid having to admit the existence of an element lighter than hydrogen.

Dr. Stuart D. Bale, UC Berkeley
Within the context of a gaseous solar model, it is not surprising that extreme temperatures must be invoked. A gaseous Sun has no other means of producing highly ionized species.
"Since the corona must be excessively hot to produce such
ions in a gaseous context, the continuous spectrum of the K-corona
has been dismissed as a strange artifact, produced
by electronic scattering of photospheric light. Otherwise,
the coronal continuous spectrum would be indicating
that apparent coronal temperatures are no warmer than those
of the photosphere. It would be impossible for the gaseous
models to account for the presence of highly ionized
species within the outer solar atmosphere.
Current temperature estimates are
flirting with violations of both the first and second laws of
thermodynamics: it is difficult to conceive that localized temperatures
within flares and the corona could greatly exceed
the temperature of the solar core."
P.M. Robitaille
Now scientists think that the temperature of the solar corona can exceed even the temperature of the core itself.