P7.3
Turbulence spectra and vertical profiles of energy dissipation rate and temperature structure parameter in thin turbulent layers embedded in a stably stratified environment
Andreas Muschinski, CIRES/University of Colorado and NOAA/ERL/ETL, Boulder, CO; and R. M. Worthington, R. G. Frehlich, M. L. Jensen, and B. B. Balsley
In the stably stratified atmosphere (nocturnal boundary layer and free atmosphere), small-scale turbulence tends to organize itself in thin layers. The layers can have thicknesses of down to several meters, possibly even less. Relatively little is known about the vertical profiles of fine-scale turbulence characteristics (e.g., energy dissipation rate, e, temperature structure parameter, CT2, etc.) within such layers. More detailed knowledge could be relevant for a deeper understanding of clear-air radar and lidar remote sensing measurements and for improved turbulence parameterization. High-resolution fine-scale turbulence measurements using a vertically spaced array of fine-wire sensors carried with the CIRES TLS (CIRES: Cooperative Institute for Research in Environmental Sciences - TLS: Tethered Lifting System) were collected in Kansas in October 1999 during CASES-99. In this contribution, spectra of turbulent temperature and wind-speed fluctuations, and vertical profiles of e and CT2 across turbulent layers are presented. Spectra and profiles are discussed on the basis of simple mixing-length and inertial-range scaling arguments, and with view on previous observations and simulations.
Poster Session 7, Stable
Wednesday, 9 August 2000, 6:00 PM-9:00 PM
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