The Role of Gravity Waves in Slowly Varying in Time Mesoscale Motions

Abstract

Abstract Pressure oscillations with amplitudes of the deviations from the horizontal mean and periods considerably less than those for the large-scale case have been observed in a number of summer and winter storms. However, there is conflicting evidence about the role of these waves in mesoscale storms. In the case of mesoscale heating that is a prescribed function of the independent variables, it has been proven that the dominant component of the corresponding slowly varying in time solution is accurately described by a simple dynamical (reduced) system in which gravity waves play no role. This paper proves that large spatial-scale gravity waves with amplitudes and periods of the pressure perturbations the same as the reduced system component of the solution can be generated by mesoscale storms. Because the amplitudes and the periods of the pressure perturbations for the two components of the solution are similar, it is difficult to distinguish between them using temporal plots of the pressure at a sing...