Retrieval of intrinsic mesospheric gravity wave parameters using lidar and airglow temperature and meteor radar wind data

Abstract. We analyze gravity waves in the mesosphere, lower thermosphere region from high-resolution temperature variation measured by Rayleigh lidar and OH temperature mapper. From this combination of instruments, aided by meteor radar wind data, the full set of ground-relative and intrinsic gravity wave parameters are derived by means of the novel WAPITI method. This Wavelet Analysis and Phase line IdenTIfication tool decomposes the gravity wave field into its spectral components while preserving the temporal resolution, allowing us to identify and study the evolution of gravity wave packets in the varying background. We describe WAPITI and demonstrate its capabilities for the large-amplitude gravity wave event on 16/17 December 2015 observed at Sodankyla, Finland, during the GW-LCYCLE-II field campaign. We present horizontal and vertical wavelengths, phase velocities, propagation directions and intrinsic periods including uncertainties. The results are discussed for three main spectral regions, representing short, medium and long-period gravity waves. We observe a complex superposition of gravity waves at different scales, partly generated by gravity wave breaking, evolving in accordance with a vertically and presumably also horizontally sheared wind.