Gravity-wave-perturbed wind shears derived from SABER temperature observations

Based on previous observations using sounding rockets, lidars, radars, and model simulations, large shears are mainly attributed to gravity waves (GWs) and modulated by tides (Liu, 2017). Based on the dispersion and polarization relations of linear GWs and the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) temperature data from 2002 to 2019, a method of deriving GW-perturbed wind shears is proposed.

The zonal-mean GW-perturbed shears have peaks (13-17 ms(-1) km(-1)) at around the mesopause region, i.e., at z = 90-100 km at most latitudes and at z = 80-90 km around the cold summer mesopause. This latitude-height pattern is robust over the 18 years and agrees with model simulations. The magnitudes of the GW-perturbed shears exhibit year-to-year variations and agree with the lidar and sounding rocket observations in a climatological sense but are 60 %-70 % of the model results in the zonal-mean sense.