PowerPoint Presentation - Ray Tracing of Gravity Waves in Vortex Dipoles

Summary

ĄGravity waves are simulated at the jet exit regions associated with dipoles. In the surface dipole case, gravity waves are generated near the surface and do not propagate above 5km at later time. In the mid-level dipole case, gravity waves are generated near the jet exit region and propagate both upward and downward. Gravity waves generated from a tropopause level dipole propagate upward mostly.

ĄFour dimensional ray tracing model accommodates the temporal and spatial variations of the background wind from the dipole simulation. Our results show that as the gravity waves propagate upward, wave characteristics changes significantly.

ĄHorizontal and vertical wave wavelength decreases.

ĄIntrinsic group velocity decreases but never vanishes. Wave packets are finally almost advected by weak mean wind.

ĄIntrinsic frequency are close to inertial frequency.

ĄHow gravity waves are generated has not been fully understood. Spontaneous wave emission could be most possibly generation mechanism for gravity waves in vortex pairs.