Animations

Animation 1: 3D simulation of orographic gravity waves forced by a 200-km-wide, 1000-m-high isotropic compact-cosine mountain using the WRF model. Left: Zonal winds (color shaded) and isentropes (contoured) are shown in the x-z slice through the middle of the 3-D domain evolving through 48 hrs of the simulation. Right: Zonal winds (color shaded) are shown in an x-y slice through z = 65 km. The single contour shows the spatial extent of the mountain. The WRF setup here is a 3-D extension of that described by Kruse and Smith (2018). Buoyancy frequency, N, is 0.02 s^-1 and and constant environmental zonal mean wind of 30 m s^-1 was specified. At t=24 hrs the low level winds are forced towards zero. Animation by C. Kruse [ckruse@ucar.edu].

Animation 2: Vertical structure of the breakdown of the 3-D orographic gravity waves shown in Animation 1, but at t = 18.33 hours. In the left panel, the thick horizontal black line depicts the level at which the x-y cross-section is shown in the right panel. Simulation and animation by C. Kruse [ckruse@ucar.edu].

Animation 3: 3D simulation of convectively generated gravity waves using the Complex Geometry Compressible Atmospheric Model (CGCAM) [Felton and Lund (2006)]. Latent heating is used as a proxy for convection. Left panel shows a cross=section at z=85 km, whereas the right panel shows a vertical cross-section through the center of the domain. Shading indicates vertical velocity perturbations. Solid thin line depicts the background zonal mean wind profile. Animation courtesy of C. Heale [ healec@erau.edu].

Animation 4: The evolution of gravity waves based on the weak moist run from the high-resolution idealized baroclinic wave simulations in Wei and Zhang (2014). Left: The horizontal view of the simulated 1-km temperature (yellow lines: ∆=5K), 7-km dynamic tropopause where potential vorticity equals 1.5 PVU (turquoise lines), 8-km horizontal wind (black lines; contours at 40, 45, 50, and 55 m s^-1, and 12-km horizontal divergence (blue lines, positive; red lines, negative; ∆=2.0×10^-6 s^-1; range within ±1.2x10^-5 s^-1; zero value omitted). Right: The vertical cross section along the green line in the left panel for the simulated potential temperature (yellow lines: ∆=5K), dynamics tropopause where potential vorticity equals 1.5 PVU (turquoise lines), horizontal wind (black lines; contours at 30, 35, 40, 45, 50, 55, 60 and 65 m s^-1), and horizontal divergence (blue lines, positive; red lines, negative; ∆=2.0×10^-6 s^-1; range within ±1.2×10^-5 s^-1; zero value omitted). Animation courtesy of J. Wei [ weijunh@mail.sysu.edu.cn].

References:

Felten, F. N., and T. S. Lund (2006), Kinetic energy conservation issues associated with the collocated mesh scheme for incompressible flow, J. Comput. Phys., 215, 465–484. [Link]

Kruse, C. G. and R. B. Smith, 2018: Non-Dissipative and Dissipative Momentum Deposition by Mountain Wave Events in Sheared Environments. Journal of the Atmospheric Sciences, Doi: 11.1175/JAS-D-17-0350.1 [Link]

Wei, J., and F. Zhang, 2014: Mesoscale gravity waves in moist baroclinic jet–front systems. J. Atmos. Sci., 71, 929–952, Doi: 10.1175/JAS-D-13-0171.1 [Link]