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

为了更好地描述水在大气中的四维分布，以便更好地了解其对深对流的影响，国际H20项目(IHOP-2002)将于2002年5月至6月在大平原南部进行实地实验。IHOP的四个重点领域是：1)定量降水预报(QPF)；2)对流启动；3)大气边界层过程；4)仪器研究。首席研究人员将在数值定量降水预报的背景下进行风暴尺度的研究，重点是湿度敏感性和数据同化。具体地说，他们将：1.开发新的和改进的技术，特别是基于变分方法，在单个对流风暴及其更大的中尺度集群的尺度上分析和同化水和相关的非绝热场(例如潜热和感热)。研究对水汽和水流星含量的特殊和常规高分辨率观测对预报一至几公里分辨率的对流风暴形态和定量降水的影响。正向模型和伴随模型都将用于评估敏感度和数据影响。发展和评估对流尺度数值预报误差特征(即误差协方差矩阵)的估计技术，以提高三维和四维变分数据同化的质量。将新开发的单多普勒速度和热力学反演算法应用于IHOP期间收集的移动雷达数据，并将反演的数据同化到预报模式中。5.提供6至12小时范围的实时、高分辨率(2-3公里)分析和预报，以协助在IHOP实地阶段进行业务决策和确定流动观测的目标。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。这些研究成果将通过作为天气研究和预报(WRF)模式系统开发项目的牵头科学家之一的PI参与直接运作。尽管由于风暴分析和预报中心(CAPS)高级区域预报系统(ARPS)的成熟性和能力，这里要执行的大部分工作都将使用，但只要有可能，就会使用新的WRF。此外，作为履约协助方案参与世界粮食安全框架项目的一部分，这里获得的结果和开发的软件将用于进一步开发世界粮食安全框架模型。

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.