Mesoscale Structures and Dynamics of Mid-Latitude Cyclones

中纬度气旋的介尺度结构和动力学

• 批准号: 9632580
• 负责人: Peter Hobbs
• 金额: $ 90.69万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-12-01 至 2000-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9632580&HistoricalAwards=false
• 关键词: Mesoscale; Structures; Dynamics; Mid; Latitude

9632580 Hobbs Cyclones in middle latitudes affect large regions of the world. Consequently, improvements in understanding and forecasting of weather associated with middle-latitude cyclones has been one of the major goals of 20th century meteorology. Although very significant advances have been made in the basic understanding and ability to forecast extratropical cyclones on the large (synoptic) scale, progress in forecasting local precipitation and severe weather associated with these systems has been much slower. This is attributed to insufficient understanding of processes and phenomena on the convective scale (~0.1-10 km) and mesoscale (~10-1000 km). For the past twenty years or so, the cloud physics research group at the University of Washington has studied extratropical cyclones, with emphasis on the microphysics and mesoscale aspects of precipitation. These studies led to a classification and study of rainbands on the west coast of the United States, and studies of cyclones on the US east coast and in the central US. The latter two studies led to a proposal for a new conceptual model for cyclones that are generated in the lee of the Rocky Mountains, as well as to the identification of two large-scale rainbands that can produce severe weather in the central United States. The present research is an extension of these studies. Three main areas of research will be pursued. The first is to carry out further evaluations of the new conceptual model for cyclones in the central United States in order to improve its observational and theoretical foundation, and to increase its utility as a weather forecasting aid. The second task is to investigate the mechanisms responsible for the formation of narrow cold frontal rainbands, which are a ubiquitous feature of extratropical cyclones and can produce severe local weather. The formation of wide cold-frontal rainbands, another common feature of cyclones, will also be investigated. These studies will be carried out through detailed analyses of special data sets collected in three already completed field projects, and through numerical modeling studies of these cases using an advanced mesoscale model. ***

9632580 中纬度地区的霍布斯气旋影响世界大部分地区。 因此，提高对中纬度气旋相关天气的了解和预报一直是 20 世纪气象学的主要目标之一。 尽管在大范围（天气）温带气旋的基本认识和预报能力方面已经取得了非常重大的进步，但预报与这些系统相关的局地降水和恶劣天气的进展却要慢得多。这是由于对对流尺度（~0.1-10 km）和中尺度（~10-1000 km）的过程和现象认识不足。 在过去二十年左右的时间里，华盛顿大学的云物理研究小组一直在研究温带气旋，重点是降水的微物理和中尺度方面。 这些研究导致了对美国西海岸雨带的分类和研究，以及对美国东海岸和美国中部气旋的研究。 后两项研究提出了关于落基山脉背风处产生的气旋的新概念模型的建议，并确定了两个可能在美国中部产生恶劣天气的大规模雨带。 目前的研究是这些研究的延伸。 将开展三个主要研究领域。 首先是对美国中部气旋的新概念模型进行进一步评估，以改善其观测和理论基础，并提高其作为天气预报辅助工具的效用。 第二个任务是研究狭窄的冷锋雨带形成的机制，这是温带气旋的普遍特征，可以产生恶劣的局地天气。 宽阔的冷锋雨带的形成是气旋的另一个共同特征，也将受到调查。这些研究将通过对三个已完成的现场项目中收集的特殊数据集进行详细分析，并使用先进的中尺度模型对这些案例进行数值建模研究来进行。 ***