The Turbulent Gravity Wave-Critical Level Evolution of Atmospheric Flow.
Abstract
Strong turbulence may be produced when an internal gravity wave encounters a critical level. This turbulence can dissipate the wave motion, so that the momentum transported by the wave is deposited into the mean flow. Thus, gravity wave-critical level encounters are a significant mechanism by which the wind may be modified by gravity waves. Such an encounter has been computed. The rms turbulent velocities are seen to be a substantial fraction (some 25%) of the wave-induced velocity. The absorption of the wave is seen to alter the wind profile, with turbulence distributing the wave momentum flux above and below the critical level. A variety of features of the wave and turbulence motion may be extracted. One which will be useful for comparison with radar observations is the refractive index structure function (C sub n) - squared and contour plots are displaced. Several other quantities depicting the evolution of the encounter also are presented. Plans for a detailed analysis of these and new computations are outlined. Also discussed are comparisons of these calculations with Doppler radar observations and laboratory measurements.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 19, 1986
- Accession Number
- ADA177274
Entities
People
- John R. Grant