Large winds and wind shears caused by the nonlinear interactions between gravity waves and tidal backgrounds in the mesosphere and lower thermosphere

摘要: A two-dimensional nonlinear numerical model was used to simulate large winds (>= 100m s(-1)) and wind shears 40m s(-1) km(-1)) in the mesosphere lower thermosphere (MLT) that are caused by interaction between gravity waves (GWs) migrating tidal background. By varying wavelengths of GWs phases diurnal semidiurnal tides, 64 experiments were performed. Our indicate both tides strongly modulate occurrence GW breaking, resulted shears. The simulated good agreement with those from rocket-sounding chemical release measurements. Moreover, highly depends on local time, which is reported lidar observations. time dependence mainly attributed filtering and/or hindering effects GWs. simulation reveals interactions breaking may play an important role driving MLT region their dependence.