An Idealized Ray Model of Gravity Wave-Tidal Interactions
Abstract
The interaction of a gravity wave with a solar tide is analyzed using ray theory in order to assess whether the temporal oscillation of the tide has any significant effects on the interaction. We consider two types of solution: a "full ray solution," in which tidal accelerations are included in the gravity wave ray-tracing equations, and a second "Lindzen solution," in which they are neglected; the latter is so named because it yields similar results to the parameterization of Lindzen [1981]. Initially, we consider an idealized tide of constant velocity amplitude in a steady isothermal atmosphere, as this allows analytical solutions to be derived. A numerical ray-tracing code is employed to determine ray solutions within more complex tidal backgrounds. Full ray solutions often differ markedly in amplitude, wavenumber, and trajectory from Lindzen solutions for the same wave, highlighting the importance of tidal accelerations. Tidal accelerations have a stabilizing influence on gravity wave amplitudes by refracting waves to larger intrinsic phase speeds, thus reducing both the occurrence and intensity of tidally modulated gravity wave breaking.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 27, 1996
- Accession Number
- ADA530955
Entities
People
- Crispin J. Marks
- Stephen D. Eckermann
Organizations
- United States Naval Research Laboratory