ИСТИНА

Comparison of the Balmer series lines with HXR and microwave emissions. are used as tools for study of the chromospheric response to effects of accelerated particle beams in solar flares. It is known from the theoretical simulations of (Kasparova & Heinzel, 2002) that the beam could also influence ratios between the Balmer lines. We study the optical spectra the H-alpha and H-betta lines and the ratio of the line profiles for several solar flares obtained with a high cadence to find and analyze predicted variations. The profiles extracted at individual kernels during different flare phases are analyzed with respect to the radio and X-ray data. We found that the theoretical predictions of the H-alpha/H-betta line profile ratios and the observations were in a good qualitative agreemen t. However, as concerns quantitative correspondence, we found some difference in position of the predicted profile ratio maxima, moment of arising and the duration of the effect, influence of energy cutoff of electron beam. We try to find some explanations for those discrepancies and discuss perspectives of simultane- ous observations of Balmer series lines.