Stratospheric gravity wave characteristics and seasonal variations observed by lidar at the South Pole and Rothera, Antarctica

The gravity wave spectra are derived from the atmospheric relative density perturbation in the altitude range of 30 - 45 km measured by an iron Boltzmann lidar. The ground-relative wave characteristics obtained at each location are comparable, with an annual mean vertical wavelength of ~4.1 km, vertical phase speed of ~0.7 m s⁻¹, and period of ~104 min.

Approximately 44% of the observed waves show an upward phase progression while the rest display a downward phase progression in ground-based reference for both locations. Gravity wave potential energy density (GW-EP) at Rothera is ~4 times higher than the South Pole in winter but is comparable in summer. Clear seasonal variations of GW-EP are observed at Rothera with the winter average being 6 times larger than that of summer.