Accession Number:

ADA525029

Title:

A Simplified Fourier Method for Nonhydrostatic Mountain Waves

Descriptive Note:

Journal article

Corporate Author:

NAVAL RESEARCH LAB CHESAPEAKE BEACH MD CHESAPEAKE BAY DIV

Report Date:

2003-11-01

Pagination or Media Count:

12.0

Abstract:

A previously derived approximation to the standard Fourier integral technique for linear mountain waves is extended to include nonhydrostatic effects in a background flow with height-dependent wind and stratification. The approximation involves using ray theory to simplify the vertical eigenfunctions. The generalization to nonhydrostatic waves requires special treatment for resonant modes and caustics. Resonant modes are handled with a small amount of damping, and caustics are handled with a uniformly valid approximation involving the Airy function. This method is developed for both two- and three-dimensional flows, and its results are shown to compare well with an exact analytical result for two-dimensional mountain waves and with a numerical simulation for two- and three-dimensional mountain waves.

Subject Categories:

  • Numerical Mathematics
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE