Nonlinearly selected frequencies in coronal loops

A nonlinear process lor the resonant generation of low-frequency last magnetosonic kink waves in coronal loops is discussed. The efficiency of the process is strongly enhanced due to the existence or a nonlinearly selected frequency produced by a constant frequency difference in the dispersion curves in the short wavelength limit. The kink wave with the selected frequency interacts with high-frequency kink and sausage waves. The efficiency of such interaction docs not require coherence in the interactive waves, in a loop of width 2 × 10³ km, field strength 50 G und number density 5 × 10¹⁵ m^-3, the nonlinearly selected frequency is of order 46 mHz. (period 21.8 s), but this may range through 11 mHz to 184 mHz (periods 86.5 s to 5.4 s) for typical coronal conditions.