Simulations of MILs in the MLT Region Using a Quasi-linear Full-wave Model

The presence of the mesospheric inversion layer (MIL) has attracted attention recently. The exact mechanism of its formation remains debatable and is still been investigated. A favorable theory for the formation of the MILs is that mean-state forcing by gravity wave coupled with tides instigates the instability of the atmosphere and the heat energy from the instability causes the temperature increase, thus forming the MIL. A quasi-linear full-wave model is employed to study the formation of the MILs. Several scenarios are proposed for the simulations: Gravity-wave forcing acting alone or Gravity-Wave coupling with tides with a high-altitude wave source or a low altitude wave source. Our preliminary results show that a small amplitude gravity wave coupling with tides could produce larger temperature variations than by the gravity wave forcing alone. While a high-altitude source is scarce compared with a low-altitude source, our studies show that a small amplitude wave forcing from a high-altitude source could cause large temperature perturbations that would normally require a large amplitude wave from a low-altitude wave source.