REMOTE-SENSING OBSERVATIONS OF WINTER AIRCRAFT ICING CONDITIONS - A CASE-STUDY

This article describes how various combinations and arrays of remote s ensors can be used to successfully predict aircraft icing conditions a loft. A case study, validated by pilot reports, is developed to illust rate the use of remote sensor data to predict aircraft icing condition s as well as verify icing forecasts. Surface-based remote sensing inst ruments and conventional instruments were used to study aircraft icing conditions during the winter storm of January 24-25, 1989, in the Den ver, Colorado area. A unique combination of arrays of remote sensors w as used to determine spatial and temporal distribution of supercooled liquid water. The remote sensors used were profiling radars, radio-aco ustic sounding systems, multichannel microwave radiometers, and lidar ceil-ometers. Measurements used to predict aircraft icing conditions a loft included cloud liquid water, temperature profiles with high verti cal (similar to-150 m) and temporal (similar to-15 min) resolutions, a nd the heights of cloud base, as well as estimates of cloud-top height with a temporal resolution of 15 min. Arrays of remote sensing instru ments are shown to enhance detection and prediction of aircraft icing. Present and future remote sensing capabilities for detecting aircraft icing events are described. This icing case study is unique in combin ing arrays of remote sensors of various types to define the spatial an d temporal distributions of supercooled liquid water, and in making co mparisons with pilot reports as a means of verification.