Convectively generated gravity waves influence the circulation in the middle atmosphere by depositing momentum to the flow at their breaking levels. Global Circulation Models do not resolve convectively generated gravity waves and therefore the gravity wave spectrum generated by convection must be parameterized. In order to properly parameterize such a spectrum gravity wave generation by convection must be understood.

In this work we present a new method of describing the gravity waves generated by convection that gives a fairly complete representation of the wave spectrum since it includes gravity waves generated both by the oscillatory and steady components of the convective heating, and it includes the effects of environmental wind shear on the wave spectrum.

Firstly we show that the momentum flux phase speed spectrum of gravity waves generated by convection in motionless basic state can be determined from the knowledge of the vertical and horizontal scales of convection and its temporal distribution. These three parameters determine the dominant vertical wavelength and therefore the intrinsic wave phase speed of convectively generated gravity waves. The gravity wave spectrum is symmetric in the east-west directions in a motionless atmosphere, however this is drastically altered by the presence of mean wind in and above the heating region. We present a method of describing the changes in the momentum flux phase speed spectrum under various environmental shear distributions both in and above the forcing region. Environmental wind shear interacts very differently with the oscillatory and steady components of the thermal forcing, therefore inclusion of both components is crucial to proper representation of convectively generated gravity.