Interaction of gravity waves propagating from the lower atmosphere with local Joule heating

Abstract:

We study the gravity wave induced perturbations with and without local Joule heating using the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIEGCM). Gravity waves from the theoretical model are nudged to the lower boundary of TIEGCM. The sensitivity of the wave amplitudes to the number of nudging vertical levels, nudging parameters, and nudging time step are examined to produce the most efficient manner to allow the waves to penetrate through the nudging areas. We find that a larger number of nudging vertical levels, grouped with exponentially decreasing weighting of the nudging with altitude, and nudging U, V, and T components, are more efficient than smaller number of nudging levels, rigid nudging, and nudging all U, V, T, and Z components. As the local Joule heating is present, gravity waves propagating from the lower atmosphere can excite larger magnitudes of perturbations, likely due to the background elevation such as in temperature. The local Joule heating enhancement may act as an amplifier for waves propagating from below. The ion drag, ion drifts, and circulation patterns due to the interaction of gravity waves and Joule heating are also examined.