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Ann. Geophys., 23, 2401-2413, 2005
www.ann-geophys.net/23/2401/2005/
© European Geosciences Union 2005
Turbulence parameter estimations from high-resolution balloon temperature measurements of the MUTSI-2000 campaign
N. M. Gavrilov1, H. Luce2, M. Crochet2, F. Dalaudier3, and S. Fukao4
1Saint-Petersburg State University, Atmospheric Physics Department, Petrodvorets, 198504, Russia
2Laboratoire de Sondages Electromagnétiques de l’Environnement Terrestre, Université de Toulon et du Var, France
3Service d’Aéronomie du CNRS, BP3, 91371, Verrières le Buisson, Cedex, France
4Research Institute for Sustainable Humanosphere, Kyoto University, Uji, 611-0011, Japan
Abstract. Turbulence parameters in the tropo-stratosphere are analyzed using
high-resolution balloon temperature measurements collected during the MUTSI
(MU radar, Temperature sheets and Interferometry) campaign which took place
near the Middle and Upper atmosphere (MU) radar (Japan, 35° N, 136° E)
in May 2000. Vertical profiles of the specific dissipation rate of turbulent
kinetic energy, ε, and turbulent diffusivity, K, are estimated from the Thorpe
lengthscale, LT. The last is obtained by using two methods. The first one
consists of measuring directly LT by reordering the potential
temperature profiles. The second method is based on estimates of the temperature
structure constant, CT2. A relationship between LT and
CT2 can be found by assuming either adiabatic vertical displacements
or a model based on turbulent energy balance consideration. Analysis shows
that the adiabatic assumption gives indirect estimates of LT more
consistent with direct measurements. We also found that vertical profiles of
analyzed turbulence characteristics show substantial intermittency, leading
to substantial scatter of the local, median and average values. General
trends correspond to a decrease in ε and K from the boundary layer up to altitudes
20–25 km. Layers of increased turbulence are systematically observed in
the tropo-stratosphere, which may be produced by instabilities of
temperature and wind profiles. These maxima may substantially increase local
values of turbulence diffusivity.
Keywords. Meteorology and atmospheric dynamics (Turbulence)
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