Performance of radar-based in-flight icing detection algorithms compared to vibrating wire sondes

During the winter of 2015, twenty-four vibrating wire supercooled liquid water sondes were released during twelve separate in-flight icing events from the NASA Glenn Research Center in Cleveland, Ohio. If the vibrating wire sonde encountered a cloud layer which contains supercooled liquid, the liquid drops froze instantly to the wire. The vibrating wire's frequency is known to decrease at a rate proportional to the mean diameter of the supercooled water and the liquid water content of the drops it comes in contact with. These in-situ measurements of supercooled liquid are compared to output from two different ground-based remote-sensing techniques – the first utilizes operational NEXRAD moments and the second uses output from a vertically pointing cloud radar and a radiometer. The magnitude and altitude of supercooled liquid are assessed for each algorithm compared to the in-situ data for the twelve in-flight icing events and related results are discussed.