Solar Flare is a phenomenon which takes place by the magnetic energy release
in the solar corona. Generated thermal and bulk Kinetic energy is stored
in a magnetic loop, re-distributed inside it, and the loop is cooled
down. The magnetic loop contains most of its component in the high
temperature and low density corona but its feet are conected to the low
temperature and high density chromospheric atomosphere on the surface of the
Sun. When the energy released by the flare in the corona comes over to the
chromosphere, its temperature and pressure increase rapidly, and an upward
flow of the high density plasma toward corona is formed by the pressure
gradient created. As a result, flare loop is filled by the high density
plasma and soft X-ray is emitted by its thermal bremsstrahlung. This kind of
upward flow of the plasma is called as "chromospheric evaporation" and
obsered as blue shifts of X-ray emission lines. Here, we will simulate
energy re-distribution process in the flare loop.
To show initial states, please place the mouse on figures.
Initially there are two layers; high density chromosphere and high
temperature corona. Coronal region is heated by the flare and the energy
released is transered to the chromosphere. As a result, upward flow of the
chromospheric gas toward corona is formed.
Hydrodynamic equation with thermal conduction and radiation cooling.
Here, gamma = 5/3 is the ratio of specific heat, S is
cross section, g is gravity acceleration, H is static heating term, R is
radiation cooling term, Hf is flare heating term, kB
is Boltzmann constant, m is mean particle weight, g0 is the
gravity at the photosphere (x=0), and kappa0 is a constant
determined by gas property. As a heat diffusion coefficient we take Spitzer
model.
Please refer THIS document (pdf file in Japanese)
as a detailed explanation.