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Estimates of turbulent parameters in the lower stratosphere‐upper troposphere by radar observations: A novel twist
Author(s) -
Dole J.,
Wilson R.
Publication year - 2000
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1999gl010766
Subject(s) - stratosphere , troposphere , richardson number , turbulence , thermal diffusivity , dissipation , physics , radar , atmospheric sciences , isotropy , computational physics , meteorology , optics , thermodynamics , telecommunications , computer science
The turbulence parameters in the upper troposphere‐lower stratosphere are estimated from the backscattered power of a VHF radar located at the Observatoire de Haute‐Provence (OHP). Under the classical framework of locally homogeneous and isotropic turbulence, we propose a slightly different method for estimating the turbulent diffusivity from radar measurements. The temperature structure parameter, C T ² , and the vertical heat diffusivity, K θ , are expressed as a function of the dissipation rate of the temperature variance, ϵ θ (and not from the dissipation rate of kinetic energy). This parameter appears weakly dependent on unknown quantities such as the mixing efficiency R f /(1‐ R f ) ( R f is the flux Richardson number) and the vertical stratification . Our estimations of ϵ θ are of the same order as in situ measurements. The inferred diffusivity K θ appears considerably weaker (one order of magnitude) than radar estimates using the bandwidth of the Doppler spectrum.