How variable are gravity wave spectral energies? Insights from a seven-year lidar climatology at 69°N

Despite significant progress in observational and theoretical studies on gravity wave (GW) dynamics, gaps remain in characterizing their variability and accurately representing their impact on the average state of the atmosphere in models. In particular, there is an altitudinal gap in estimating the kinetic and potential energy spectra of GWs between 30 and 70 km.

This study investigates the seasonal and altitudinal variations of GW energy spectra using high-resolution temperature and horizontal wind data recorded over seven years (2017-2023) by a Doppler Rayleigh lidar at the ALOMAR observatory (69°N, 16°E). We analyze spectral potential and kinetic energies across different frequencies and vertical wavenumbers to quantify the variability of dominant wave scales, amplitudes and spectral slopes. We also estimate the temporal and spatial variability of kinetic to potential energy ratio and its implication for the intrinsic values of observed GW frequencies. The findings aim to improve estimates of the atmospheric energy budget, compare theoretical predictions to observed data, and advance our understanding of the GW natural variability.