Eddy Dissipation Rates in Thunderstorms Estimated by Doppler Radar in Relation to Aircraft In Situ Measurements

Abstract

Abstract High-resolution aircraft turbulence measurements, well coordinated with radar Doppler spectral width measurements, have been used to verify radar-estimated energy dissipation rates within thunderstorms anvils. The radar-estimated eddy dissipation rates have been carefully interpolated in time and space to the aircraft position. From the aircraft measurements, turbulence was estimated using a three-component averaged structure function D(r). The sensitivity of this structure function to r, to wind components selected, and to the sampling rate was investigated. Power spectra for all three wind components have been derived for selected flight sections. Differences between these three spectra and deviations from the k−5/3 law indicate areas of energy input. At areas where all three spectra follow the k−5/3 law, indicating the inertial subrange of turbulence, both estimates of the energy dissipation rate by aircraft and radar agree rather well. On average an overestimation of the dissipation rate by r...