Solar Flares in White Light and Heating of the Solar Photosphere by Alfvén Waves

Abstract

Alfvén waves with periods of a few seconds excited in solar coronal magnetic loops during flare energy release can lead to effective heating of the plasma in the lower atmosphere of the Sun, which is responsible for continuous optical radiation. Meanwhile, the question of the propagation time of these modes from the corona to the photosphere has not yet been considered in detail. Based on solar atmospheric model by Avrett and Loeser (2008), for different values of background magnetic fields, taking into account their height dependence, the estimates of the propagation time of Alfvén waves from the corona to the photosphere were obtained. The characteristic values exceeding several minutes and impose certain restrictions on wave heating of the lower atmosphere of the Sun. The implications of the results are discussed.