Tropical Storms: A Bridge Between Formation and Intensification

在过去十年中，美国国家海洋和大气管理局及其合作的联邦机构在飓风生命周期的逐渐早期阶段提供了观测资料。因此，通过机载原位传感器、全球定位系统（GPS）投风探空仪以及机载常规雷达和多普勒雷达的组合，更频繁地观测到热带风暴（TS，被命名为持续风速为17-32米/秒的系统）。NOAA、NASA和美国空军飓风侦察中队维护的现有数据档案是本研究的关键信息来源，进一步利用这些数据档案提供了一种理想的经济方法。关于TS形成机制和随后的快速强化的持续不确定性阻碍了更准确的预报和预警；对上述数据集进行更全面的检查可能会对TS的形成、这些暖核风暴的后续演变以及最终导致更高级别飓风发展的过程提供深入的了解。由GPS探空仪阵列获得的详细大气剖面图将客观地结合飞行水平和体积雷达数据，在发展中的TS事件中心200公里范围内，重点关注对流层低层结构和近地面风暴流入。美国空军的连续侦察飞行提供了理想的时间分辨率（即每6-12小时快照）。全球再分析数据集将用于描述风暴的大尺度环境。这些场将进一步揭示环境因素的影响，如水平风的深层垂直切变和中层干空气对内部风暴特征的影响，包括发展中的圆形眼壁和封闭眼区、螺旋雨带和大气边界层的相关能量输入。本研究的智力价值在于对发展中的热带风暴的反射率、运动学和热力学结构得到更全面的描述；风暴核心附近等效位温升高的来源及其在形成过程中的作用；暖湿低层流入流向发展核心区；中尺度对流涡在TS发展中的作用。关于TS形成的相互竞争的理论（即所谓的“自上而下”或“自下而上”机制）将利用这些先前未开发的观测结果进行批判性评估，并将探索区分热带风暴达到飓风状态和未达到飓风状态的条件。导出的场将作为热带风暴详细数值模拟的基准。通过对研究生的培训和夏威夷大学热带气象学课程的持续发展，通过加强夏威夷大学与美国国家海洋和大气管理局飓风研究部门之间的现有伙伴关系，最终通过提高更好地预测飓风发展和向公众发布准确警报的能力，这项工作将产生更广泛的影响。

Abstract for Barnes/1042680Over the last decade efforts by NOAA and cooperating federal agencies have provided observations during progressively earlier stages of the hurricane life cycle. Tropical storms (TS, which are named systems possessing sustained wind speeds of 17-32 m/s) have thus been more frequently observed via a combination of in-situ airborne sensors, Global Positioning System (GPS) dropwindsondes, and airborne conventional and Doppler radar. Existing data archives maintained by NOAA, NASA and the USAF Hurricane Reconnaissance Squadron represent key sources of information for this study, and their further exploitation is offers a desirably economical approach. Persistent uncertainties concerning mechanisms of TS formation and subsequent rapid intensification represent an impediment to more accurate forecasts and warnings; more complete examination of aforementioned datasets may provide insights into TS formation, the subsequent evolution of these warm-core storms, and ultimately those processes responsible for development of higher-category hurricanes. Detailed atmospheric profiles obtained by arrays of GPS sondes will be objectively combined flight-level and volumetric radar data within 200 km of the center of developing TS events with a focus on lower tropospheric structures and near-surface storm inflow. Serial reconnaissance flights by the USAF offer desirable temporal resolution (viz. snapshots very 6-12 hours). Global reanalysis datasets will be used to describe the large-scale environment of the storms. Together these fields will reveal further details re: the influence of environmental factors such as the deep layer vertical shear of the horizontal wind and midlevel dry air upon internal storm features including the developing circular eyewall and enclosed eye region, spiral rainbands, and associated energy inputs into the atmospheric boundary layer.The Intellectual Merit of this study rests in attaining more comprehensive descriptions of: reflectivity, kinematic and thermodynamic structures within developing tropical storms; the source of increased equivalent potential temperature near the storm core and its role in the formation process; the disposition of warm, moist low-level inflow directed toward the developing core; and the role of the mesoscale convectively generated vortex in TS development. Competing theories of TS formation (viz. so-called "top-down" or "bottom-up" mechanisms) will be critically evaluated using these previously untapped observations, and conditions differentiating tropical storms that attain hurricane status and those that do not will be explored. Derived fields will serve as a benchmark for detailed numerical simulations of tropical storms.Broader Impacts of this work will be derived through the training of graduate students and the continued development of classes in tropical meteorology offered at the University of Hawaii, by enhancement of a existing partnerships between the University of Hawaii and NOAA's Hurricane Research Division, and ultimately through improved ability to better anticipate hurricane development and issue accurate warnings to the public.