Propagation of whistler mode waves with a modulated frequency in the magnetosphere

[1] This paper presents results from experimental and numerical studies of the propagation of whistler mode waves in the Earth’s magnetosphere. An experiment conducted at the High Frequency Active Auroral Research Program (HAARP) on 16 March 2008 demonstrates that ionospherically generated waves with particular frequency‐time formats are amplified on their pass from HAARP to the conjugate location in the South Pacific Ocean more efficiently than waves with a constant frequency. Numerical simulations of a one‐dimensional electron magnetohydrodynamics (MHD) model in the dipole magnetic field geometry reveal that the amplification takes place more efficiently when the frequency of the whistler mode waves (in the frequency range from 0.5 to 1.0 kHz) changes in the equatorial magnetosphere with the rate from 0.25 to 0.47 kHz/s. The maximum amplification occurs when this rate is 0.33 kHz/s and no/very little amplification is observed when this gradient is equal to 0 or when it is larger than 0.78 kHz/s.