An overview of observations of unstable layers during the Turbulent Oxygen Mixing Experiment (TOMEX)

Academic Article


  • The Turbulent Oxygen Mixing Experiment (TOMEX) was designed to measure the atmospheric response to the existence of unstable layers as determined by wind and temperature measurements from 80 to 105 km. TOMEX combined Na lidar measurements, from Starfire Optical Range in Albuquerque, New Mexico, with a launch of a payload from White Sands Missile Range, located between 100 and 150 km south of Starfire. The payload included a trimethyl aluminum chemical release to measure winds and diffusion, a 5‐channel ionization gauge to measure neutral density fluctuations at high vertical resolution, and a 3‐channel photometer experiment to measure atomic oxygen related airglow. The rocket was launched when the lidar data indicated the presence of convectively and dynamically unstable regions between 80 and 100 km altitude. For several hours prior to the launch, there had existed a large amplitude atmospheric gravity wave or tide which brought the background atmosphere into being nearly convectively unstable over the 85 to 95 km region. In addition a large overturning in Na density, possibly due to a convective roll, existed at altitudes around 100 km. This type of instability had not been previously seen and identified in this altitude region. The TOMEX payload measured the existence of Kelvin‐Helmholz billows, enhanced neutral density fluctuations, enhanced energy dissipation, and well‐mixed regions. These features were associated with convectively unstable regions, dynamically unstable regions, convective rolls, and the presence of this large wave. The unstable regions were persistent and covered large vertical (and horizontal regions) of the atmosphere. The atmospheric mixing and energy dissipation appeared to be largely determined by the presence and nature of these instabilities.
  • Authors

  • Hecht, JH
  • Liu, AZ
  • Bishop, RL
  • Clemmons, James
  • Gardner, CS
  • Larsen, MF
  • Roble, RG
  • Swenson, GR
  • Walterscheid, RL
  • Status

    Publication Date

  • January 21, 2004
  • Keywords

  • composition
  • mesospheric dynamics
  • turbulence
  • Digital Object Identifier (doi)


  • 109
  • Issue

  • D2