MULTIWAVELENGTH OBSERVATIONS OF A DEVELOPING CLOUD SYSTEM - THE FIRE-II 26 NOVEMBER 1991 CASE-STUDY

Simultaneous multiwavelength measurements of a developing cloud system were obtained by NOAA Doppler lidar, Doppler radar, Fourier transform infrared interferometer, and microwave and infrared radiometers on 26 November 1991. The evolution of the cloud system is described in term s of lidar backscatter, radar reflectivity and velocity, interferomete r atmospheric spectra, and radiometer brightness temperature, integrat ed liquid water, and water vapor paths. Utilizing the difference in wa velength between the radar and lidar, and therefore their independent sensitivity to different regions of the same cloud, the cloud top, bas e, depth, and multiple layer heights can be determined with better acc uracy than with either instrument alone. Combining the radar, lidar, a nd radiometer measurements using two different techniques allows an es timation of the vertical profile of cloud microphysical properties suc h as particle sizes. Enhancement of lidar backscatter near zenith reve aled when highly oriented ice crystals were present. The authors demon strate that no single instrument is sufficient to accurately describe cirrus clouds and that measurements in combination can provide importa nt details on their geometric, radiative, and microphysical properties .