Adam Kelly, V.M. Nakariakov and T.D. Arber,  University of Warwick

Observations of flaring loops in radio, visible and x-ray bands show
quasi-periodic pulsations with periods in the range 10-300s. Recent numerical
studies have shown that these oscillations can be interpreted as standing slow
magnetoacoustic waves. Energy deposition from the flare, through the
chromospheric evaporation, excites the second standing harmonic, with the
period determined by the temperature and the loop length. The excited
longitudinal oscillations are practically dissipationless and can, possibly, be
considered as MHD autowaves. Numerical simulations with a wide range of flare
durations and choices of heat deposition location show that the second harmonic
is a common feature of flaring loops.