On a method of determination of parameters in the initial phase of chromospheric flares

The results are given on calculation of a model for the initial phase of a chromospheric flare within the scope of the theory of a power gasodynamic explosion with account of all the substantial dissipation processes. A method is proposed to determine initial values of density rho0 and mass M0 in the region of the explosion. The method enables one to describe the observed value of the total energy E0 and time dependence of change in the velocity of the forefront of a chromospheric flare luminescence. It is found that the greater is E0, the higher is the altitude of flare appearance in the chromosphere. Here, the growt.h of M0 is followed by the increase in the ratio of rho0 to density of nondisturbed chromosphere at the level of flare appearance. An empirical relation is found between E0 and M0 at the electron temperature Tsub(e) of a nondisturbed chromosphere at the level of flare appearance: Esub(O)=8.33x10sup(12)Msub(0)Tsub(e) for flares with the radius r0 approximately 107 cm, E0 and M0 are less than 1029 erg and 1O12 g respectively, and flares appear in the lower chromosphere. For the most power flares, values of E0, Tsub(e) and M0 are 1033 erg, 104 K and 1016 g respectively, which agrees with experimental data