Cloud, Precipitation, and Aerosol Research at FARS: The Facility for Atmospheric Remote Sensing

University Of Utah, Salt Lake City UT

Investigators

Abstract

This grant supports an ongoing research program investigating aerosols, clouds, and precipitation, using the unique capabilities of the Facility for Atmospheric Remote Sensing (FARS) at the University of Utah. Instruments include visible, infrared, and microwave radiometers, a ruby (0.694 micrometres wavelength) Cloud Polarization Lidar (CPL), a scanning dual-wavelength (0.532 and 1.06 micrometres) high-resolution Polarization Diversity Lidar (PDL), and a W-band (3.2 millimetres) polarimetric Doppler radar. To this battery of equipment will be added a nitrogen Raman channel for the PDL, which will enable the determination of the aerosol extinction coefficient independently of the backscattering coefficient, and provision for scanning the PDL in elevation, to study the shapes and orientations of hydrometeors and the anisotropy of clouds as scattering media. Emphasis to now has been on improving fundamental understanding of midlatitude cirrus clouds by monitoring their spectral scattering and emission properties as they move over the FARS site. New objectives include the study of precipitation development in mixed-phase (ice and water) clouds, investigations of the shapes and orientations of ice crystals as revealed by their optical and microwave properties, and studies of the optical properties and vertical structure of aerosol layers that originate from local and sometimes distant sources. The work is highly relevant to the interpretation of present and proposed satellite remote sensing measurements and to the treatment of clouds and aerosols in climate models.