New Perspectives on Storm Track Dynamics, Variability, and Change

中纬度风暴路径是全球环流的重要组成部分。沿风暴路径移动的气旋主导着日常天气变化，风暴路径活动或位置的变化强烈影响区域气候变化。构成风暴路径的斜压波也负责在中纬度地区向极地输送大部分热量、水分和动量。因此，了解风暴路径的动力学和变率，以及它们在未来如何变化，是非常重要的。将对为政府间气候变化专门委员会第五次评估报告（IPCC AR5）准备的耦合模式比对项目（CMIP5）进行诊断分析，该项目由多个最先进的气候模式模拟。风暴路径的两个方面——风暴能量和气旋频率和强度——将进行研究，为风暴路径动力学、变率和变化提供全面的新视角。将最先进的气候模式模拟的风暴路径与再分析数据得出的风暴路径进行比较，以记录模式偏差，以及不同气候模式之间风暴路径变率和变化的差异。利用模式模拟的空前质量和多样性，将研究气旋频率和强度与平均流量变率之间的关系。这些研究的结果将提供对隐藏在模型偏差和差异背后的物理过程的见解，并提供关于这些偏差和差异如何影响模型预测的新想法。

Mid-latitude storm tracks form an important part of the global circulation. Cyclones passing along the storm tracks dominate the day-to-day weather variability, and changes in storm track activity or location strongly impact regional climate variations. Baroclinic waves that make up the storm tracks are also responsible for transporting much of the heat, moisture, and momentum poleward in the midlatitudes. Thus, the understanding of storm track dynamics and variability, as well as how they may change in the future, is of great importance.Diagnostic analyses of the Coupled Model Intercomparison Project (CMIP5), simulations by multiple state-of-the-art climate models, prepared for the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5) will be undertaken. Two aspects of storm tracks--storm energy and cyclone frequency and strength--will be examined to provide comprehensive new perspectives of storm track dynamics, variability and change. Storm tracks simulated by state-of-the-art climate models will be compared to those derived from reanalysis data to document model biases, and differences in storm track variability and change among the different climate models. Making use of the unprecedented quality and diversity of model simulations, the relationship between cyclone frequency and strength and mean flow variability will be examined. Results of these studies will provide insights on the physical processes that lurk behind model biases and differences, and furnish new ideas regarding how these biases and differences might impact model projections.