Thermal Metamorphosis of the Solar Atmosphere

Vita-Finzi C

Published on: 2024-05-10

Abstract

The rise in temperature from ~ 4 10³ K at the solar photosphere to ≥ 1-2 10⁶ K at the outer corona occurs in three steps which are triggered or delayed by factors analogous to the hormones that govern holometabolous insect metamorphosis. Ohmic heating raises the temperature of the photosphere to ~8 10³ K and the chromosphere to ~ 10⁴ K; the inverse Joule-Thomson process takes the transition region to 10⁶ K, and plasma expansion then accelerates ions to the high energies manifested as the solar wind. There is no Newtonian conflict with the gradient implied by this progression. The stepwise solar model may be applicable to other bodies displaying a radial increase in temperature and decrease in plasma density.