A Study of the Energy Deposits in Flaring Atmosphere with Semiempirical Models of Flares

Using the time-varying semiempirical models for two flares (one is classified as a SBflare and the other a 2Bflare), which were deduced from the spectral data obtained with the solar tower telescope of Nanjing University, the radiative loss at different phases of the flares are computed and compared with the energy deposits due to electron beam bombardment and X-ray radiation. The results show that the variation of chromospheric radiative loss during the flares is more than one order of magnitude. It is also shown that during the impulsive phase of the flares the heating due to the electron beam bombardment is very efficient, but for the gradual phase of the flares, the energy deposits mechanism due to X-ray is a better one than that due to electron beam in order to explain the observational results, whereas near the intensity maximum of the flares, both X-ray and electron beam have their contributions. The results indicate that the heating in the lower chromosphere and the upper photosphere, especially for large flares, can be caused neither by X-ray radiation nor by electron beam bombardment. It seems that there are some other mechanism to transpot the deposit energy from the upper part of the atmosphere to the lower part. This study also shows that time-varying models of flares are good tools in the investigation of the flare energy balance.