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GEOPHYSICAL RESEARCH LETTERS, VOL. 33, L08808, doi:10.1029/2005GL024345, 2006

Intense turbulence observed above a mesospheric temperature inversion at equatorial latitude

G. A. Lehmacher

Department of Physics and Astronomy, Clemson University, Clemson, South Carolina, USA


C. L. Croskey

Communications and Space Sciences Laboratory, Department of Electrical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA


J. D. Mitchell

Communications and Space Sciences Laboratory, Department of Electrical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA


M. Friedrich

Institute for Communications Networks and Satellite Communication, Graz University of Technology, Graz, Austria


F.-J. Lübken

Leibniz-Institute for Atmospheric Physics, Kühlungsborn, Germany


M. Rapp

Leibniz-Institute for Atmospheric Physics, Kühlungsborn, Germany


E. Kudeki

Department of Electrical and Computer Engineering, University of Illinois, Urbana, Illinois, USA


D. C. Fritts

Colorado Research Associates, Northwest Research Associates, Boulder, Colorado, USA


Abstract

Results from a sounding rocket experiment launched on September 19, 2004 from Kwajalein Atoll, Marshall Islands are reported. A large modulation of the temperature profile in the upper mesosphere was observed with a local maximum at 92 km, 40 K warmer than 2 km below. The temperature gradient between 92 and 102 km was near-adiabatic, suggesting strong mixing. Turbulence was observed in the lower part of the mixed layer, as evidenced by neutral and plasma density fluctuations on both the upleg and downleg portions of the flight. The plasma density gradient was less steep in the mixed region. The turbulent energy dissipation rate was found to be 170 mW/kg. The thermal structure can be described as an upper mesospheric inversion layer, possibly caused by enhanced wave breaking or turbulent heat transport.

Received 9 August 2005; accepted 6 October 2005; published 28 April 2006.

Index Terms: 0342 Atmospheric Composition and Structure: Middle atmosphere: energy deposition (3334); 3332 Atmospheric Processes: Mesospheric dynamics; 3334 Atmospheric Processes: Middle atmosphere dynamics (0341, 0342); 3369 Atmospheric Processes: Thermospheric dynamics (0358).

Subscriber Access to Full Article (Nonsubscribers may purchase for $9.00, Includes print PDF, file size: 301354 bytes)

Citation: Lehmacher, G. A., C. L. Croskey, J. D. Mitchell, M. Friedrich, F.-J. Lübken, M. Rapp, E. Kudeki, and D. C. Fritts (2006), Intense turbulence observed above a mesospheric temperature inversion at equatorial latitude, Geophys. Res. Lett., 33, L08808, doi:10.1029/2005GL024345.