A numerical model characterizing internal gravity wave propagation into the upper atmosphere

摘要: Abstract A new two-dimensional, time-dependent and fully nonlinear model is developed to numerically simulate plane wave motions for internal gravity waves in a non-isothermal windy atmosphere that accounts the dissipation due eddy molecular processes. The has been treated as well mixed total gas with constant mean weight. effects of Rayleigh friction Newtonian cooling are applied near upper boundary radiation conditions act sponge layer; lateral boundaries periodic over horizontal wavelength horizontally infinite domain. thermal excitation initiate upward propagating spatially localized troposphere Gaussian function time. time-splitting technique finite difference equations derived from Navier–Stokes equations. time integration these highly coupled performed using an explicit second order Lax–Wendroff scheme implicit Newton–Raphson scheme. solutions found be broadly agreeable those Wentzel–Kramers–Brillouin theory.