Tropical Cyclone Structure and Dynamics Based on Data from the Hurricane Rainband and Intensity Experiment (RAINEX)

基于飓风雨带和强度实验 (RINEX) 数据的热带气旋结构和动力学

• 批准号: 0743180
• 负责人: Robert Houze
• 金额: $ 103.1万
• 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: 2008
• 资助国家: 美国
• 起止时间: 2008-03-15 至 2014-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0743180&HistoricalAwards=false
• 关键词: Tropical; Cyclone; Structure; Dynamics; Based

The Hurricane Rainband and Intensity Change Experiment (RAINEX) documented the 2005 Hurricanes Katrina, Ophelia and Rita. In conjunction with NOAA's Intensity Forecasting Experiment, RAINEX was the first hurricane project to 1) combine the use of three Doppler radar-equipped aircraft, 2) use the high-definition NSF Electra Doppler Radar (ELDORA) in hurricanes, and 3) use real-time ground-based flight coordination to optimize the placement of aircraft within the storms. RAINEX also deployed dropsondes (released at 5 min intervals on each Doppler flight leg) and was guided by the use of real-time high-resolution numerical forecasts. RAINEX was unusually successful in that it documented some of the most interesting hurricanes in the history of the U.S. and the data set was of extremely high quality. This research will exploit the RAINEX data in studies aimed at understanding tropical cyclone phenomenology in relation to hurricane intensity changes. The ELDORA data and dropsondes will be analyzed to: 1) Document details of evolving storm structure during the eyewall replacement cycle of Rita; in particular, the relationship of convective-scale circulation anomalies to the developing wind maximum in the secondary eyewall and differences between the secondary and primary (inner) eyewalls. 2) Document and interpret the principal rainbands in Katrina and Rita when each storm was at Category 5 intensity. 3) Synthesize the circulation within a convective burst leading to the development of Hurricane Ophelia. The possible contribution of the extremely deep, wide, and persistent updraft in the burst to cyclogenesis will be evaluated. 4) Analyze the influx of dry air into the rainbands of Hurricane Ophelia to determine if the dry air intrusion takes the form of a mesoscale unsaturated downdraft. 5) Analyze how the pattern of small-scale structures observed by ELDORA changed as Rita came under the influence of large-scale shear. 6) Compare the convective structures of outer rainbands in all three storms to interior rainbands that are more strongly affected by the primary vortex. The analysis of ELDORA and dropsonde data in the above studies will include determination of the three dimensional (3D) latent heating structures associated with the slantwise convection of eyewalls, the discrete convective cells of rainbands and within a secondary eyewall, the stratiform regions of rainbands, and the ordinary convection of far outer rainbands. From these calculations, the implications of the 3D latent heating pattern to the storm circulation structure and associated rainband and eyewall dynamics will be inferred. This study will include collaborative efforts to assimilate RAINEX Doppler radar and dropsonde analyses into numerical forecasts and ultimately to transfer RAINEX experience to operational forecast centers. Intellectual merit: The study builds on the PI's previously established expertise in the dynamics and physics of tropical convection, tropical cyclones, and other types of atmospheric clouds and precipitation systems. Results will provide valuable new information to increase basic understanding related to prediction of hurricane intensity changes. Broader impacts: This study will contribute to the societal goal of improving predictions of hurricanes and associated extreme wind, coastal storm surge and flash flood events that have a devastating impact on life and property in coastal regions.

飓风雨带和强度变化实验(RAINEX)记录了2005年的卡特里娜飓风、奥菲莉亚飓风和丽塔飓风。与NOAA的强度预测实验相结合，RAINEX是第一个1)结合使用三架配备多普勒雷达的飞机，2)在飓风中使用高清晰度NSF Electra多普勒雷达(Eldora)，以及3)使用实时地面飞行协调来优化飞机在风暴中的位置的飓风项目。RAINEX还部署了落点探测仪(在每个多普勒飞行支线上每隔5分钟释放一次)，并由实时高分辨率数值预报进行指导。RAINEX非常成功，因为它记录了美国历史上一些最有趣的飓风，而且数据集的质量非常高。这项研究将在旨在了解与飓风强度变化有关的热带气旋现象的研究中利用RAINEX数据。将分析Eldora资料和滴水探测仪，以记录RITA眼壁更换周期期间演变的风暴结构的细节；特别是对流尺度环流异常与次级眼壁发展风最大值的关系以及次级眼壁和初级(内)眼壁之间的差异。2)记录和解释卡特里娜和丽塔每次风暴强度为5级时的主要雨带。3)合成导致飓风奥菲莉亚发展的对流爆发内的环流。将评估爆发中极深、极宽和持续的上升气流对气旋生成的可能贡献。4)分析干空气进入奥菲莉亚飓风雨带的情况，以确定干空气入侵是否以中尺度非饱和下沉气流的形式存在。5)分析Eldora观测到的小尺度结构在大尺度剪切作用下如何变化。6)比较三个风暴的外部雨带和受主涡影响较大的内部雨带的对流结构。上述研究中对Eldora和Dropsonde数据的分析将包括确定与眼壁的倾斜对流有关的三维(3D)潜热结构、雨带和次级眼壁内的离散对流单元、雨带的层状区以及遥远外部雨带的普通对流。从这些计算中，可以推断3D潜热模式对风暴环流结构以及相关的雨带和眼壁动力学的影响。这项研究将包括合作努力，将RAINEX多普勒雷达和投放探空仪分析同化为数值预报，并最终将RAINEX经验转移到业务预报中心。智力优势：这项研究建立在PI之前在热带对流、热带气旋和其他类型的大气云和降水系统的动力学和物理方面的专业知识的基础上。结果将提供有价值的新信息，以增加对飓风强度变化预测的基本了解。更广泛的影响：这项研究将有助于提高对飓风及相关极端风、沿海风暴潮和对沿海地区生命财产造成毁灭性影响的山洪事件的预测的社会目标。