Cloud and Precipitation Studies Using a Millimeter-Wavelength Radar

将利用94 GHz多普勒雷达的观测以及低频雷达和现场仪器的辅助观测来增进我们对关键的云和降水过程的认识和理解。这些系统将提供评估云分辨率和显式云模型所需的高分辨率观测，并评估远程测量降水的技术。重点是在热带/亚热带环境中观察到的浅对流和深对流以及层状降水。迈阿密大学(UM)94 GHz雷达的高灵敏度，其高分辨率的时间和空间采样，以及先前研究中开发的多普勒频谱处理技术，将使PI能够扩展他对降水和非降水云系的动力学和微物理结构的研究。这项研究的科学目标是：1)描述层状雨中小尺度垂直速度结构和水滴尺寸分布的垂直结构，研究蒸发如何影响其垂直结构；2)研究融化层上方的云的微物理和动力学如何影响在融化层以下的层状雨中观测到的微物理和垂直空气速度。除了雷达观测外，还将获得高空探测和地面雨量测量，以提供有关环境和云条件的更多信息。虽然在整个为期3年的项目期间，将在弗吉尼亚州基州的UM校园进行机会性观测，但计划在2008年8月至9月进行密集的观测。佛罗里达州南部的位置允许对海风引发的对流-层状系统以及与热带扰动通过该地区或其附近移动有关的系统进行采样。广泛影响：这些研究将导致雷达观测技术，这对更广泛的雷达和遥感社区具有重要意义。为这项研究开发的多波长能力将大大增强美国研究仪器基础设施的现有雷达能力。将向科学界提供所生成的数据集，以支持超出该项目直接科学重点的应用。使用试验性快扫描相控阵多普勒雷达将能够机会主义地观测到登陆飓风的外部雨带。这些研究还将有助于了解可用于发展星载雷达应用的云和降水特性。95 GHz和更长波长的雷达联合行动代表了美国大学独特的活动，为加强雷达气象学本科生和研究生教育提供了有效手段，并增加了公众对物理气象学技术和科学进步的了解。

Observations from a 94 GHz Doppler radar with supporting observations from lower-frequency radars and in situ instruments will be used to improve our knowledge and understanding of key cloud and precipitation processes. These systems will provide high resolution observations needed to evaluate cloud resolving and explicit cloud models, and to evaluate techniques for measuring precipitation remotely. The focus is on both shallow and deep convection, and stratiform precipitation, observed in a tropical/subtropical environment. The high sensitivity of the University of Miami (UM) 94 GHz radar, its high resolution temporal and spatial sampling, and the Doppler spectral processing techniques developed in previous studies will allow the PI to extend his studies of the dynamical and microphysical structure of precipitating and non-precipitating cloud systems. The scientific objectives of this study are to: 1) characterize the vertical structure of the small-scale vertical velocity structures and drop size distributions in stratiform rain and study how evaporation affects their vertical structure, and2) examine how the microphysics and dynamics of clouds above the melting layer affect the microphysics and vertical air velocities observed in stratiform rain just below the melting layerA technological objectives of this study is to further develop the observing techniques pioneered by the UM group. In addition to the radar observations, upper-air soundings and surface rainfall measurements will be obtained to provide additional information on environmental and cloud conditions. Although opportunistic observations will be made throughout the duration of the 3-year project from UM's campus site on Virginia Key, an intensive observational period is planned for August-September of 2008. The south Florida location allows for sampling of both sea-breeze initiated convective-stratiform systems and those associated with tropical disturbances moving through or in the vicinity of the area.Broader Impacts: The studies will lead to radar observational techniques that are of importance to broader radar and remote sensing community. The multiwavelength capability developed for this study will substantially enhance the existing radar capabilities of the US research instrumentation infrastructure. Data sets generated will be made available to the scientific community to enable applications beyond those of the direct scientific focus of this project. The use of an experimental fast-scan phased array Doppler radar will enable opportunistic observations of outer rainbands of land-falling hurricanes. These studies will also lead to an understanding of cloud and precipitation characteristics that can be used in the development of space-borne radar applications. The combined 95 GHz and longer wavelength radar operations represent a unique US university activity and provide an effective means of enhancing undergraduate and graduate education in radar meteorology and increasing public understanding of the technological and scientific advances in physical meteorology.