Reply on RC2

Abstract

<strong class="journal-contentHeaderColor">Abstract.</strong> The convectively generated gravity waves (GWs) have important contributions on the stratospheric and mesospheric momentum and energy budget, and chemical composition, however, large uncertainties still remain about wave source properties and the associated wave-generated mechanisms. The formation mechanism and significant impacts of downward propagating GWs generated by a continental overshooting hailstorm occurred on 19 June 2017 in Beijing in the mid-latitude are reported in this study based on radar observations and simulated results from a three-dimensional cloud model with hail-bin microphysics. It is found that the overshooting storm penetrates the tropopause and enters the lower stratosphere in the mature stage. After the mature stage, the continuous descending process of the upper-level high graupel/hail loading causes the breaking of equilibrium between the buoyancy force and hydrometeor loading established in the mature stage and induces a restoring force of buoyancy, as well as buoyancy oscillations that excite downward propagating GWs. The GWs have a duration of about 20 min and the estimated wavelength of about 3&ndash;4 km. The downward propagating GWs not only result in the storm updraft splitting quickly, and significantly change the storm morphology and evolution, but also form the upward propagating GWs through surface reflection process, and induce strong vertical fluctuations in temperature and vertical velocity, and significantly change the dynamic and thermodynamic structure in the lower stratosphere.