Determining the Phase of the Diurnal, Solar Thermal Tidal Wave in the Upper Atmosphere Using Nighttime Na Lidar Measurements

Solar thermal tidal waves play a critical role in the dynamics of the mesosphere and thermosphere. Obtaining measurements of the diurnal tidal wave above 100 km is difficult. This could be solved using a physics-based empirical model. To derive this model requires knowing the phase at different points along the tidal wave. In this study, I determine the phase at multiple points along the thermal diurnal tidal wave using measurements taken by a fluorescence lidar in the range of 80 to 100 km. A simple calculation of the phase based on the zeroes and extrema of the wave is demonstrated