This is a 3-year modeling effort to be undertaken as part of the Coupling, Energetics and Dynamics of Atmospheric Regions program. Atmospheric gravity waves are believed to play a vital role in the transport of energy and momentum between atmospheric layers. This transport is enabled by the propagation of these waves vertically through the background atmosphere and dissipation of these occurs via the growth of instabilities (both convective and shear instabilities). This project utilizes two advanced numerical simulations to investigate gravity wave and instability processes in the Mesosphere-Lower Thermosphere (MLT) region. Previous simulations have been performed in idealized environments and small periodic domains. Here, the simulations will be extended to deep domain studies, which will examine these wave and instability processes in more realistic flows inspired by detailed observations.
Gravity waves are a significant forcing source on MLT dynamics and their effects strongly impact general circulation and climate models. In addition, numerical weather prediction models, despite their tropospheric focus, have been shown to make better predictions when the upper-atmospheric dynamics are more accurately modeled. Specifically, improved understanding of when / where gravity waves become unstable in realistic flows that would result from this effort is a vital step towards improving parametrization of these waves in global-scale models.
