Variability and extremes of poleward breaking Rossby waves over the North Atlantic - European Region (VARNAER)

北大西洋 - 欧洲地区 (VARNAER) 极地破碎罗斯比波的变化和极端情况

• 批准号: 60884280
• 负责人: Privatdozent Dr. Dieter H.W. Peters
• 金额: --
• 依托单位: Abteilung Modellierung atmosphärischer Prozesse
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/60884280?language=en
• 关键词: Variability; extremes; poleward; breaking; Rossby

In the extratropics Rossby waves play an important role in determining the general circulation, especially in the upper troposphere / lower stratosphere region. It is known that events of poleward breaking Rossby waves are often observed over the North Atlantic-European region in wintertime. In this project we investigate the influence of the observed background flow in the upper troposphere on poleward Rossby wave breaking events and the link to severe weather. We will study the intra-seasonal and interannual variability of events of poleward breaking Rossby waves over the North Atlantic-European region and diagnose the extreme cases of the wave breaking events for each season, based on ECMWF Reanalysis (ERA-INTERIM) and analyses. The predictability of such events is investigated by using different forecasts data sets. Furthermore, the expected influence of the different zonally varying background flows on poleward Rossby wave breaking will be examined in simplified global ECHAM5 model simulations in order to improve the understanding of this process. A further key investigation is the diagnosis and mesoscale modelling (WRF) for implications of poleward Rossby wave breaking events on the change of the Grosswetterlage (large scale flow) in the lower troposphere, in order to examine different acting mechanisms, and to understand the sub-seasonal differences of the influence and of the impact on severe weather over Northern Europe.

在温带地区，罗斯比波对大气环流起着重要的决定作用，特别是在对流层上层/平流层下层。众所周知，冬季在北大西洋-欧洲地区经常观察到向极地断裂的罗斯比波事件。在这个项目中，我们研究观测到的对流层上层背景流对极地罗斯比破波事件的影响及其与恶劣天气的联系。我们将基于ECMWF再分析（ERA-INTERIM）和分析，研究北大西洋-欧洲地区ross - by极向破波事件的季节内和年际变化，并诊断每个季节的极端破波事件。这些事件的可预测性是通过使用不同的预测数据集来研究的。此外，为了提高对这一过程的理解，将在简化的全球ECHAM5模式模拟中研究不同纬向变化背景流对极地罗斯比破波的预期影响。进一步的关键调查是对极地罗斯比破波事件对对流层下层大尺度流变化的影响进行诊断和中尺度模拟（WRF），以检验不同的作用机制，并了解影响的分季节差异以及对北欧恶劣天气的影响。