Measurement and Predictability of Local Convective Rainfall

本研究探讨了局地对流地面降雨及其伴随的地面和边界层大气变量的测量，建立了用于降雨特性和动力学基础研究的原型数据库，并确定了局地对流降雨的可预测性特性。该研究对水文学的意义在于：(1)利用精细分辨率数据增强降雨和其他风暴数据的水文数据库，有利于研究地表降雨及其极值的统计和动力特性；(2)评估在地表强降雨发生过程中起作用的基本动力学和微物理机制，为致力于动态参数化的努力提供有益的结果；(3)提供可预测性措施，这将对危险洪水事件的水文研究非常有益。一系列特别校准的地面气象测量仪器，包括非常灵敏的光学雨量计和相控阵风廓线仪，将用于测量爱荷华州爱荷华市三个地点的对流事件，在两个项目年的每个春季和夏季的四个月。质量控制的数据将用于创建一个原型数据库，该数据库将（连同文件）提供给科学界进行基础研究。这些数据还将用于协助制定以物理为基础的、与观测到的降水过程的时间特征相一致的强降雨数学模型，并可用于评估当地地面降雨的可预测性。//

This study addresses measurement of local convective surface rainfall and attendant surface and boundary layer atmospheric variables, on the creation of a prototype database for fundamental studies on rainfall properties and dynamics, and on the determination of predictability properties of local surface convective rainfall. The significance for hydrology is that the study will: (1) enhance the hydrologic database of rainfall and other storm data with very-fine resolution data with beneficial consequences for studies on the statistical and dynamical properties of surface rainfall and its extremes, (2) assess the fundamental dynamical and microphysical mechanisms at work during the occurrence of heavy surface rainfall with beneficial consequences for efforts devoted to dynamical parameterizations, (3) provide predictability measures that would be very beneficial for hydrologic studies of hazardous flood events. A host of specially calibrated instruments for surface meteorological measurements, including very sensitive optical raingauges and a phased array wind profiler will be used for measurement of convective events in three locations in Iowa City, Iowa during four spring and summer months of each of the two project years. The quality-controlled data will be used to create a prototype database that would be made available (together with documentation) to the scientific community for fundamental studies. The data will also be used to aid in the formulation of mathematical models of heavy rainfall that are physics-based and consistent with the observed temporal features of the process and that could be used to assess the predictability properties of local surface rainfall.//