Cirrus Structure and Radiative Parameters from Airborne Lidar and Spectral Radiometer Observations: The 28 October 1986 FIRE Study

Abstract Remote sensing lidar and imaging spectral radiometer observations were obtained from the ER-2 high-altitude research aircraft during the 1986 FIRE cirrus missions. The dual polarization lidar measurements were nadir directed with 7.5 m vertical and 40 m horizontal resolution, and clearly depicted structure at the top and within the cirrus. Simultaneous radiometric cloud top images were acquired with 5 mrd resolution at ten visible channels, three infrared window channels, and four near-infrared channels. The combined lidar and radiometer data were analyzed for the cirrus structure, radiative parameters, and inferred microphysical properties. On 28 October 1986 a cirrus formation crossed Wisconsin. The results indicate that for the eastern edge of the formation there was a cirrus layer at 9 to 11 km altitude, and a separate lower cloud at 7 to 8 km. The lidar depolarization indicated the upper layer was ice crystals, the lower layer was ice in some areas, and water or possibly mixed phase in other...