The Gravity Wave Response above Deep Convection in a Squall Line Simulation

Abstract

High-frequency gravity waves generated by convective storms likely play an important role in the general circulation of the middle atmosphere. Yet little is known about waves from this source. This work utilizes a fully compressible, nonlinear, numerical, two-dimensional simulation of a midlatitude squall line to study vertically propagating waves generated by deep convection. The model includes a deep stratosphere layer with high enough resolution to characterize the wave motions at these altitudes. A spectral analysis of the stratospheric waves provides an understanding of the necessary characteristics of the spectrum for future studies of their effects on the middle atmosphere in realistic mean wind scenarios. The wave spectrum also displays specific characteristics that point to low physical mechanisms within the storm responsible for their forcing. Understanding these forcing mechanisms and the properties of the storm and atmosphere that control them are crucial first steps toward developing... Abstract High-frequency gravity waves generated by convective storms likely play an important role in the general circulation of the middle atmosphere. Yet little is known about waves from this source. This work utilizes a fully compressible, nonlinear, numerical, two-dimensional simulation of a midlatitude squall line to study vertically propagating waves generated by deep convection. The model includes a deep stratosphere layer with high enough resolution to characterize the wave motions at these altitudes. A spectral analysis of the stratospheric waves provides an understanding of the necessary characteristics of the spectrum for future studies of their effects on the middle atmosphere in realistic mean wind scenarios. The wave spectrum also displays specific characteristics that point to low physical mechanisms within the storm responsible for their forcing. Understanding these forcing mechanisms and the properties of the storm and atmosphere that control them are crucial first steps toward developing...