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

这项拨款支持一项正在进行的研究项目，该项目利用犹他大学大气遥感设施（FARS）的独特能力，调查气溶胶、云层和降水。仪器包括可见光、红外线和微波辐射计、红宝石（波长0.694微米）云偏振激光雷达（CPL）、扫描双波长（0.532和1.06微米）高分辨率偏振分集激光雷达（PDL）和w波段（3.2毫米）偏振多普勒雷达。在这组设备中，将为PDL增加一个氮气拉曼通道，使其能够独立于后向散射系数确定气溶胶消光系数，并提供在高程扫描PDL，研究水成物的形状和方向以及作为散射介质的云的各向异性。目前的重点是通过监测中纬度卷云在FARS站点上空移动时的光谱散射和发射特性，提高对中纬度卷云的基本认识。新的目标包括研究混合相（冰和水）云中降水的发展，研究冰晶的光学和微波特性所揭示的形状和方向，以及研究来自本地和有时来自远处的气溶胶层的光学特性和垂直结构。这项工作与目前和拟议的卫星遥感测量的解释以及气候模式中云和气溶胶的处理高度相关。

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.