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

飓风雨带和强度变化实验（RAINEX）记录了2005年的卡特里娜、奥菲莉亚和丽塔飓风。与NOAA的强度预报实验相结合，RAINEX是第一个飓风项目，1)结合使用三架装备多普勒雷达的飞机，2)在飓风中使用高清NSF埃勒克特拉多普勒雷达（ELDORA）， 3)使用实时地面飞行协调来优化飞机在风暴中的位置。RAINEX还部署了下投探空仪（每隔5分钟释放一次多普勒飞行段），并使用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，数据集的质量非常高。本研究将利用RAINEX数据进行研究，旨在了解热带气旋现象与飓风强度变化的关系。通过对ELDORA数据和下沉探空仪的分析：1)记录丽塔眼壁更换周期内风暴结构演变的细节；特别是对流尺度环流异常与次级眼壁最大风发展的关系以及次级眼壁与初级眼壁（内）的差异。2)记录和解释卡特里娜和丽塔在每次风暴达到5级强度时的主要雨带。3)综合导致飓风奥菲莉亚发展的对流暴内环流。将评估爆发中极深、极宽和持续的上升气流对气旋形成的可能贡献。4)分析干燥空气涌入飓风奥菲莉亚的雨带，以确定干燥空气入侵是否以中尺度不饱和下降气流的形式出现。5)分析丽塔在大尺度剪切作用下，ELDORA观测到的小尺度结构模式发生了怎样的变化。6)比较三次风暴中外围雨带与受主涡影响更强的内部雨带的对流结构。在上述研究中，对ELDORA和dropsonde数据的分析将包括确定与眼壁斜对流、雨带和次级眼壁内的离散对流单元、雨带的层状区域以及远外雨带的普通对流相关的三维（3D）潜在加热结构。根据这些计算，将推断出三维潜热型对风暴环流结构和相关雨带和眼壁动力学的影响。该研究将包括合作努力，将RAINEX多普勒雷达和落差探空分析融入数值预报，并最终将RAINEX的经验转移到业务预报中心。智力优势：该研究建立在PI先前在热带对流、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学方面建立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认识。更广泛的影响：这项研究将有助于提高对飓风和相关极端风、沿海风暴潮和山洪事件的预测，这些事件对沿海地区的生命和财产造成毁灭性影响。

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.