Characteristics of internal waves in the Martian atmosphere obtained on the basis of an analysis of vertical temperature profiles of the Mars Global Surveyor mission

An original method of determining the characteristics of an internal gravity wave (IGW) was developed using the data of an analysis of individual vertical temperature profile in the planet’s atmosphere. The method is based on an analysis of relative wave amplitude determined from the vertical temperature profile, as well as on the proposition of the IGW linear theory, according to which the wave amplitude is limited by the processes of dynamic (shear) instability in the atmosphere. It is supposed that, when the amplitude of the internal wave reaches the shear instability threshold as the wave propagates upward, a dissipation of wave energy occurs such that the IGW amplitude is maintained at the atmospheric instability threshold. The application of the developed method to vertical temperature profiles obtained from radio occultation measurements of the MGS ( Mars Global Surveyor ) mission made it possible to identify IGWs in the Martian atmosphere and determine the values of key wave parameters such as intrinsic frequency, amplitudes of the vertical and horizontal disturbances of wind velocity, vertical and horizontal wavelength, intrinsic vertical and horizontal phase (and group) velocities, kinetic, potential, and total energy of IGWs per unit mass, vertical fluxes of wave energy and horizontal momentum. Identified in the Martian atmosphere IGWs, with a vertical wavelength of 4.5–8.2 km, are waves with low intrinsic frequencies close to inertial frequency. Their kinetic energy, as a rule, is greater than potential energy by an order of magnitude. The propagation of these waves causes a significant modulation of the stability of atmospheric stratification that leads to shear instability and the occurrence of thin layers of intermittent turbulence in the Martian atmosphere.