Turbulence Spectra in the Upper Troposphere and Lower Stratosphere at Periods Between 2 Hours and 40 Days

Abstract

Zonal and meridional wind measurements made with the Poker Flat MST radar over a 40-day period are used to calculate the frequency power spectra at heights between 5.99 and 14.69 km. The winds used in the analysis are 1 h averages of samples taken every 4 min. We find that the spectra follow an f−5/3 power law in the range of periods from 2 to 50 h. If the Taylor transformation is valid in this frequency range, this would imply a k−5/3 wavenumber spectrum, corresponding to an inertial subrange for two-dimensional turbulence at the atmospheric mesoscale. These observations support and extend earlier studies which also show a −5/3 power law behavior in the atmospheric mesoscale.