NAWDEX

北大西洋波导和下游影响实验（NAWDEX）旨在为未来改进对欧洲高影响天气事件的预测提供基础。实地试验的概念来自WMO THORPEX计划，总体上对世界天气研究计划（WWRP），特别是对高影响天气（HIWeather）项目作出了贡献。一个由美国、英国、法国、瑞士和德国组成的国际联盟已申请资助一项多架飞机的行动，该行动将在北大西洋和欧洲地区加强地面观测。由于越来越容易受到高影响天气事件的影响，以及天气（例如可再生能源）对经济的影响越来越大，准确的天气预报对社会的重要性正在增加。与此同时，近年来数值天气预报经历了一场革命，广泛使用试图表示预报不确定性的集合预报。这代表了一个新的科学挑战，因为误差增长和不确定性在受潜热释放或其他非绝热过程影响的区域最大。这些地区的特点是小型结构，业务观测系统不能很好地反映这些结构，但现代机载遥感仪器可以进入这些区域。HALO将在NAWDEX中发挥核心作用，因为其远程和先进的仪器提供了独特的能力。在几天的协调飞行中，将有可能对热带气旋的湿润流入空气，温暖传送带的上升和流出以及下游脊的动力和热力学特性进行采样。NAWDEX将使用NARVAL战役中经过验证的仪器有效载荷，该有效载荷结合了水蒸气激光雷达和云雷达，辅以下投探空仪，以前所未有的细节和精度测量这些区域。HALO操作将由DLR猎鹰飞机提供支持，该飞机将配备风激光雷达系统，提供动力结构的协同测量。这些测量将允许对这些关键区域的预报误差增长的业务观测和分析系统的质量进行第一次密切有针对性的评价。它们将提供在这些地区作用的物理过程的详细知识，特别是中纬度天气系统中导致误差快速增长的机制。这将为数值天气预报系统更好地表示不确定性和更好的（概率）预报提供基础。

The North Atlantic Waveguide and Downstream Impact Experiment (NAWDEX) aims to provide the foundation for future improvements in the prediction of high impact weather events over Europe. The concept for the field experiment emerged from the WMO THORPEX program and contributes to the World Weather Research Program WWRP in general and to the High Impact Weather (HIWeather) project in particular. An international consortium from the US, UK, France, Switzerland and Germany has applied for funding of a multi-aircraft campaign supported by enhanced surface observations, over the North Atlantic and European region.The importance of accurate weather predictions to society is increasing due to increasing vulnerability to high impact weather events, and increasing economic impacts of weather, for example in renewable energy. At the same time numerical weather prediction has undergone a revolution in recent years, with the widespread use of ensemble predictions that attempt to represent forecast uncertainty. This represents a new scientific challenge because error growth and uncertainty are largest in regions influenced by latent heat release or other diabatic processes. These regions are characterized by small-scale structures that are poorly represented by the operational observing system, but are accessible to modern airborne remote-sensing instruments. HALO will play a central role in NAWDEX due to the unique capabilities provided by its long range and advanced instrumentation. With coordinated flights over a period of days, it will be possible to sample the moist inflow of subtropical air into a cyclone, the ascent and outflow of the warm conveyor belt, and the dynamic and thermodynamic properties of the downstream ridge. NAWDEX will use the proven instrument payload from the NARVAL campaign which combines water vapor lidar and cloud radar, supplemented by dropsondes, to allow these regions to be measured with unprecedented detail and precision. HALO operations will be supported by the DLR Falcon aircraft that will be instrumented with wind lidar systems, providing synergetic measurements of dynamical structures.These measurements will allow the first closely targeted evaluation of the quality of the operational observing and analysis systems in these crucial regions for forecast error growth. They will provide detailed knowledge of the physical processes acting in these regions and especially of the mechanisms responsible for rapid error growth in mid-latitude weather systems. This will provide the foundation for a better representation of uncertainty in numerical weather predictions systems, and better (probabilistic) forecasts.