Gravity Wave Modeling and Airglow Applications

Abstract

This AASERT supplemental grant supported numerical, theoretical, and observational studies of gravity wave and shear instability processes in the atmosphere and their impact on airglow layers near the mesopause. Efforts during the past year have explored new ground in vortex dynamics, extended our numerical studies toward both wave breaking and shear instability dynamics, and addressed the completion of a number of papers initiated under this AFOSR grant. Collectively, this grant has contributed enormously to our understanding of a diversity of wave and shear instability processes, the transition to turbulence in such flows, the dynamics of vorticity and turbulence, and applications to atmospheric measurements. Our studies have defined what we believe to be the important dynamics accompanying the transition to turbulence in a breaking wave, the dynamics of a vortex pair evolving in mean shear and stratification in two and three dimensions, and the implications of a variable wind environment for gravity waves observed in mesospheric airglow. More recent efforts have addressed the dynamics of twist waves and spanwise-varying vortex sheets as well as very-high-resolution KR shear instability dynamics. Interesting implications include significant anisotropy in turbulence and mixing relative to expectations of turbulence theory applied to such flows.

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Document Details

Document Type
Technical Report
Publication Date
Jun 14, 1999
Accession Number
ADA380242

Entities

People

  • David C Fritts

Organizations

  • Northwest Research Associates

Tags

Communities of Interest

  • Air Platforms
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Dynamics
  • Environment
  • Flow
  • Fluid Dynamics
  • Fluid Mechanics
  • Gravity
  • Gravity Waves
  • High Resolution
  • Instability
  • Layers
  • Measurement
  • Mechanics
  • Shear Flow
  • Three Dimensional
  • Transitions
  • Turbulence
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers
  • Research Science/Academic Research
  • Space/Atmospheric Physics.