Potential of 8-mm Radars for Remotely Sensing Cloud Drop-Size Distributions

摘要

This paper describes the use of a vertically pointing 8.6-mm-wavelength Dopplerradar for measuring drop-size spectra in clouds. The data used were collected in the Atlantic Stratocumulus Transition Experiment (ASTEX) in 1992. A radar technique for extracting information farther into the small-drop regime than previously attempted is described, and the amount of liquid residing in the cloud regime is compared with that found in the precipation regime where drop fall velocities are resolvable. Total liquid is compared with that measured with a collocated three-channel microwave radiometer. Examples of number density spectra, liquid water spectra, and flux spectra are shown and compared with what is known of these quantities from various in situ measurements by aircraft in similar clouds. Error estimates and uncertainties are discussed.