Rossby wave trains and their waveguides: dynamics, predictability and forecast errors (RW-GUIDE)

高振幅Rossby波列车可能在北大西洋欧洲地区引发恶劣天气事件。这种前兆波列的延长寿命可能被用来改进对恶劣天气事件的预报。然而，我们对Rossby波列及其波导的可预测性和预报误差的了解是有限的。我们建议首先诊断控制同尺度Rossby波列的传播以及它们的波导的形成和维持的物理和动力学过程。更具体地说，正压、斜压和非绝热的贡献将被量化。我们将使用ERA-中期和热带对流年数据集。应考虑将大量案例集中在高影响天气事件上。将使用基于位涡反演和基于轨迹分析的两种互补方法。然后，我们将从集合数据中客观地确定波列的可预测性，并从确定性的ECMWF预报中确定波导的预报误差结构。这些分析将结合起来，将可预测性和预报误差特征与支配Rossby波-波导耦合演化的物理过程联系起来。

High-amplitude Rossby wave trains can trigger severe weather events in the North-Atlantic European region. The extended lifetime of such precursor wave trains may be exploited to improve the forecast of severe weather events. Our knowledge of the predictability and forecast errors associated with Rossby wave trains and their waveguides, however, is limited. We propose to first diagnose the physical and dynamical processes that govern the propagation of synopic-scale Rossby wave trains and the formation and maintenance of their waveguides. More specifically, barotropic, baroclinic, and diabatic contributions will be quantified. We will use the ERA-interim and Year Of Tropical Convection data sets. A large number of cases shall be considered focusing on high impact weather events. Two complementary methods based on inversion of potential vorticity and on trajectory analysis will be used. We will then determine objectively the predictability of the wave trains from ensemble data, and the forecast error structure of waveguides from the deterministic ECMWF forecast. These analyses will be combined to link predictability and forecast error characteristics to the physical processes that govern the evolution of the Rossby wave – waveguide couplet.