How to Rely on Turbulence Measurements in Clouds

The knowledge of turbulence levels in clouds is of interest for safe aircraft operation, for the understanding of dynamical and micro physical cloud developments including precipitation formation and for estimating trace gas transports. The Doppler spectral width is an operational available product of Doppler Weather Radars. It is well known to be a measure for turbulence and shear within the radar resolution volume. Few use of that has been made up to now, possibly because of the unknown uncertainties in making quantitative estimates. We therefore compared estimates of the eddy dissipation rates from POLDIRAD Doppler spectral width measurements in the upper parts of deep convective clouds with well co ordinated high resolution in situ turbulence measurements by the FALCON research aircraft.