Advanced Study of Precipitation Microphysics with Multi-Frequency Polarimetric Radar Observations and Data Assimilation

更准确的短期定量降水预报(QPF)的进展取决于云分辨数值天气预报(NWP)模式中高分辨率观测的最佳使用。在可用的候选观测中，来自美国运行的S波段WSR-88D雷达网络(即将升级为双极化功能)的数据集是可用于运行和研究质量模型的最丰富的数据集。这组研究人员以前所做的努力促进了利用偏振雷达和地面散射计数据描述和恢复微物理降水颗粒类型和尺寸分布，并支持为风暴尺度数值预报模式开发基于正演算子和基于集合卡尔曼滤波的同化能力。目前项目下的努力将扩展到包括来自多波长数据的数据(包括高分辨率C波段和X波段偏振观测)，以寻求QPF的进一步改善和威胁生命和财产的恶劣天气的可能性。这一努力的智力优势集中在克服和纠正存在于较短波长的非瑞利散射效应，以允许充分利用这些额外的时刻数据来驱动更准确的数值预报模拟和(最终)短期预报。这项研究的广泛影响将通过研究生和博士后培训和资本化，美国国家海洋和大气管理局正在进行的大规模投资，为现有的运行中的WSR-88D雷达网增加双极化能力。与NOAA雷达操作中心工作人员的直接合作将促进将开发的算法和代码集成到试验台(最终可能是可操作的)环境中，并应有助于最大限度地利用关于风暴微物理特性的定量(与目前更定性的)信息。

Progress toward more accurate short-range quantitative precipitation forecasts (QPF) depends on optimal use of high-resolution observations within cloud-resolving numerical weather prediction (NWP) models. Among available candidate observations, those from the U.S. network of operational S-band WSR-88D radars (which are soon to be upgraded with dual-polarization capabilities) are among the richest datasets available for ingest by both operational- and research-quality models. Prior efforts by this group of investigators advanced the characterization and retrieval of microphysical precipitation particle type and size distributions using both polarimetric-radar and ground-based disdrometer data, and supported development of forward operators and ensemble-Kalman filter based assimilation capabilities for a storm-scale NWP model. Efforts under the current project will extend to include data from multi-wavelength data (including high-resolution C-band and X-band polarimetric observations) to seek further improvements of QPF and potential for severe weather threatening life and property.The intellectual merit of this effort centers on overcoming and correcting for non-Rayleigh scattering effects present at shorter wavelengths to allow full exploitation of these additional moment data in driving more accurate NWP simulations and (ultimately) short-term forecasts.Broader impacts of this research will occur through graduate student and postdoc training and capitalization upon an ongoing large NOAA investment in adding dual-polarization capability to the existing operational WSR-88D radar network. Direct collaboration with staff at NOAA's Radar Operations Center will facilitate integration of developed algorithms and codes into a testbed (and perhaps ultimately operational) setting, and should aid utilization of quantitative (vs. presently more qualitative) information on storm microphysical properties to the maximum extent possible.