Optimal Utilization and Impact of Water Vapor and Other High Resolution Observations in Storm-Scale Quantitative Precipitation Forecasts (QPF)

为了更好地描述大气中水的四维分布，以便更好地了解其对深层对流的影响，国际H20项目（IHOP-2002）将于2002年5月和6月在南部大平原进行实地试验。 IHOP的四个重点领域是：1）定量降水预报（QPF）; 2）对流引发; 3）大气边界层过程; 4）仪器研究。首席研究员将进行风暴尺度研究，特别强调数值定量降水预报背景下的湿度敏感性和数据同化。 具体而言，他们将：1。开发新的和改进的技术，特别是基于变分方法，用于分析和同化水和相关的非绝热场（例如，潜热加热和感热加热）在单个对流风暴及其较大的中尺度云团的尺度上.研究特别和常规可用的水蒸气和水凝物含量高分辨率观测对预测对流风暴形态和定量降水的影响，分辨率为1至几公里。 将使用前向和伴随模型来评估敏感性和数据影响。开发和评估估计误差特性的技术（即，误差协方差矩阵），以提高三维和四维变分资料同化的质量.将新开发的单多普勒速度和热力学反演算法应用于IHOP期间收集的移动的雷达数据，并将反演数据同化到预报模式中。 5.提供6至12小时范围内的实时、高分辨率（2-3公里）分析和预报，以协助在国际水文和气象学联合方案实地阶段作出业务决策和确定移动的观测目标，该项目将在变分数据同化、数值天气预报和集合预报等日益重要的领域为研究生和博士后提供急需的教育和培训。 通过PI作为天气研究和预报（WRF）模型系统开发项目的主要科学家之一的参与，研究结果将直接进入业务。 虽然由于风暴分析和预报中心的高级区域预报系统的成熟性和能力，这里要进行的许多工作将使用该系统，但只要有可能，将使用新的WRF。 此外，这里获得的结果和开发的软件将用于进一步开发WRF模型，作为CAPS参与WRF项目的一部分。

In an effort to better characterize the four-dimensional distribution of water in the atmosphere with a view toward improving understanding of its impact on deep convection, the International H20 Project (IHOP-2002) field experiment will take place over the Southern Great Plains during May and June of 2002. The four focus areas of IHOP are: 1) quantitative precipitation forecasting (QPF); 2) convective initiation; 3) atmospheric boundary layer processes; and 4) instrumentation research.The Principal Investigators will conduct storm-scale research with particular emphasis on moisture sensitivity and data assimilation in the context of numerical quantitative precipitation forecasting. Specifically, they will:1. Develop new and improved techniques, based particularly on variational approaches, for the analysis and assimilation of water and related diabatic fields (e.g., latent and sensible heating) at the scale of individual convective storms and their larger mesoscale clusters.2. Study the impact of special and routinely available, high-resolution observations of water vapor and hydrometeor content on the forecasting of convective storm morphology and quantitative precipitation at resolutions of one to a few kilometers. Both forward and adjoint models will be used to assess sensitivity and data impact.3. Develop and evaluate techniques for estimating error characteristics (i.e., error covariance matrices) of numerical forecasts at the convective scale to improve the quality of three-dimensional and four-dimensional variational data assimilation.4. Apply newly developed single Doppler velocity and thermodynamic retrieval algorithms to mobile radar data collected during IHOP and assimilate the retrieved data into a forecast model. 5. Provide real-time, high resolution (2-3 km) analysis and forecasts for ranges between 6 and 12 hours, to assist the operational decision-making and targeting of mobile observations during the field phase of the IHOP.The project will provide much needed education and training for graduate students and a post-doc in the increasingly important areas of variational data assimilation, numerical weather prediction and ensemble forecasting. The research findings will have a direct path to operations through the PI's involvement as one of the lead scientists in the Weather Research and Forecast (WRF) model system development project. Although much of the work to be performed herein will use the Center for Analysis and Prediction of Storms' (CAPS) Advanced Regional Prediction System (ARPS) owing to its maturity and capability, the new WRF will be used whenever possible. Further, the results obtained here, and the software developed, will be applied to further the development of the WRF model as part of CAPS' involvement in the WRF project.