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, and 2) 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 layer
A 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.
