Combination of lidar and model data for studying deep gravity wave propagation

Kurzfassung

The paper presents a simple and feasible method to complement ground-based middle atmospheric Rayleigh lidar temperature observations with numerical simulations in the lower stratosphere and troposphere. Validated mesoscale numerical simulations are utilized to substitute the temperature below 30 km altitude. For this purpose, hightemporal resolution output of the numerical results was interpolated on the position of the lidar in the lee of the Scandinavian mountain range. Two wintertime cases of orographically induced mountain waves are analysed. Wave parameters are derived using a wavelet analysis of the combined data set throughout the entire altitude range from the troposphere to the mesosphere. Although similar in the tropospheric forcings, both cases differ in vertical propagation. The numerical simulations reveal stratospheric wave breaking for one case whereas the mountain waves in the other case could propagate up to about 40 km altitude. The lidar observations reveal an interaction of the vertically propagating gravity waves with the stratopause leading to a stratopause descent in both cases.