Multi-scale analysis of the impact of soil moisture and boundary layer processes on convective precipitation

在该项目的框架内，研究土壤水分（SM）、蒸发蒸腾和行星边界层（PBL）水汽对QPF影响的策略将在不同尺度（局部到区域）上应用。目的是确定对流和地形诱导降水对平流层场变率和PBL中相应过程的依赖。这是通过一种创新的测量方法实现的，该方法使用了各种尺度上大量不同的SM传感器，这些传感器部分由IMK从其他来源提供，部分包含在整个COPS应用程序中。该应用包括一个SM站网络的实施，该网络基于目前各种组织的不协调测量，并辅以大量低成本的SM探头，使用地球物理方法进行二维湿度测量（可达1公里），以及使用freelinesense和反射GPS信号（可达40公里）整合SM测量。这些创新技术是在申请人研究所开发的。由于cop申请只考虑经过验证的测量技术，因此该提案的一小部分涉及改进此类仪器以达到可操作性。这些测量将成为2007年一般观察期（GOP）和对流地形诱导降水研究（COPS）的重要组成部分，并将为未来的业务测量网络提供SM站阵列所需的尺寸和分辨率的重要指导方针。将开发适合的质量控制程序和SM数据的升级算法，从点测量到德国气象服务（DWD）的业务预测模型LM （local - model）的网格大小。地表和边界层的水和能量通量将成为由IMK负责的cop实验的核心部分。将优化后的SM和大气场与其在LM和全球模型GME中的相关表示进行了比较。利用优化后的场进行LM模式运行，研究地表和边界层过程对对流降水的影响。LM模型的结果与cop活动期间的几个案例研究的观察结果进行了比较。密集观测与LM模拟相结合，可以对从PBL中的土壤水分和通量到对流开始和降水的水转移过程链进行严格的分析。通过对测量数据的全面分析，这项工作构成了整个cop战略的核心部分，旨在通过在天气预报模型LM中更好地表示过程来改进QPF。

Within the framework of this project, a strategy to study the effects of soil moisture (SM), evapotranspiration and water vapour in the planetary boundary layer (PBL) on QPF will be applied on different scales (local to regional). The aim is to identify the dependence of convectively and orographically induced precipitation on the variability of the SM field and the corresponding processes in the PBL. This is made possible by an innovative measurement approach using a very high number of different SM sensors on various scales, which are partly supplied by the IMK from other sources and partly included in the overall COPS application. This application includes the implementation of a SM station network based on presently uncoordinated measurements of various organisations and supplemented by a large number of low-cost SM probes, 2D moisture measurements using geophysical methods (up to 1 km) and integrating SM measurements using FreeLineSensing and reflecting GPS signals (up to 40 km). These innovative techniques have been developed at the applicants institute. A minor part of this proposal covers improvements of such instruments to reach operationaiity, since the COPS application considers only proven measurement techniques. The measurements will form essential parts of the General Observation Period (GOP) and the Convectively and Orographically induced Precipitation Study (COPS) in 2007 and will provide important guidelines on the required size and resolution of SM station arrays for future operational measurement networks. Suitable quality control routines and upscaling algorithms for SM data from point measurements to the grid size of the operational forecast model LM (Lokal-Modell) of the German Wearther Service (DWD) will be developed. The water and energy fluxes at the surface and in the PBL will become available as a central part of the COPS experiment under IMK responsibility. The optimised SM and atmospheric fields arejg compared to their related representation within the LM and the global model GME. LM model runs will be initiated with the optimised fields to study the impact of surface and PBL processes on convective precipitation. LM model results are compared to observations during the COPS campaign for several case studies. The combination of dense observations with LM simulations permits a rigourous analysis of the water transfer process chain from soil moisture and fluxes in the PBL to convection initiation and precipitation. The work constitutes a central part of the overall COPS strategy by thorough analyses of the measurement data and aims to improve the QPF by better process representation in the weather prediction model LM.