The Application of Global Positioning System (GPS) Sondes to Hurricane Intensity Evolution

全球定位系统 (GPS) 探空仪在飓风强度演化中的应用

• 批准号: 0735867
• 负责人: Gary Barnes
• 金额: $ 39.83万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-12-01 至 2010-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0735867&HistoricalAwards=false
• 关键词: Application; Global; Positioning; System; GPS

The Principal Investigator will study hurricane intensity changes using the substantial archive of Global Positioning System sondes (GPS sondes) deployed since 1997 from NOAA, NSF and NASA sponsored aircraft. These sondes will be combined with the aircraft radar and aircraft in-situ sensors for several hurricanes that were sampled over a considerable portion of their life. The GPS sondes provide wind and thermodynamic data from just below aircraft altitude to the sea surface in the inner core of the hurricane (eye to 300 km radial distance). Exploitation of the GPS sonde archive, maintained by the Hurricane Research Division of NOAA, is an economical approach to hurricane intensity research given the high cost of a research mission. The Principal Investigator has developed a cubic spline analysis that allows for the efficient construction of cross-sections (e.g., inflow distance-height, azimuth-height and radial distance-height) that provide unprecedented views of the lower troposphere and low-level inflow. These cross-sections will be applied at several stages of a hurricane's life to determine how the inner core wind and thermodynamic structures vary as the storm intensifies or weakens. With theses analyses the Principal Investigator will be able to determine mass and moisture inflow to the eyewall, and where the inflow layer acquires the energy necessary to create and sustain the hurricane circulation. Multiple cross-sections will allow for the detection of mesoscale asymmetries in the flow due to either environmental differences or rainbands and how they impact hurricane intensity. The derived fields will serve as a benchmark for numerical simulations of hurricanes. High energy air residing in the lower portion of the eye has been argued to boost instability in the eyewall and contribute to intensity levels that exceed those predicted from maximum potential intensity theory. A comparison between eye structure as seen with the GPS sondes jettisoned throughout the storm's life and aircraft in-situ measurements in the eyewall will increase understanding of how the lower eye thermodynamics affect intensity. The GPS sondes deployed from both the high altitude NOAA G-IV and the WP-3Ds in hurricanes a day or two prior to landfall will be used to identify the instability and the vertical shear of the horizontal winds while the storm is offshore. These critical indices will be compared to conditions diagnosed with the National Weather Service rawinsondes launched in the circulation at and after landfall. The purpose is to determine which hurricanes will spawn numerous tornadoes and how the wind and thermodynamic fields evolve at landfall. This is the first time that the GPS sondes deployed from the G-IV will be used for work beyond hurricane track improvement. The broader impacts of the research include the development of efficient sampling strategies to better probe the inner core of hurricanes undergoing intensity change, leading to improved forecasts of intensity that result in substantial safety and economic benefits to the United States. The proposal addresses issues identified by the NSF National Science Board, the NOAA Scientific Advisory Board, the American Meteorological Society, and the U.S. Weather Research Program Prospectus Development Teams. Educational benefits of the work include the training of graduate students and the continued development of hurricane classes for undergraduates and graduates. The work enhances the partnership between the University of Hawaii and NOAA's Hurricane Research Division.

首席研究员将使用自 1997 年以来在 NOAA、NSF 和 NASA 资助的飞机上部署的全球定位系统探空仪 (GPS 探空仪) 的大量档案来研究飓风强度的变化。这些探空仪将与飞机雷达和飞机现场传感器相结合，对在其生命周期相当长的一段时间内进行采样的几次飓风进行采样。 GPS 探空仪提供从飞机高度以下到飓风内核海面的风和热力学数据（眼睛至 300 公里径向距离）。鉴于研究任务的高昂成本，利用 NOAA 飓风研究部门维护的 GPS 探空仪档案是一种经济的飓风强度研究方法。首席研究员开发了三次样条分析，可以有效构建横截面（例如，流入距离-高度、方位角-高度和径向距离-高度），从而提供对流层低层和低层流入的前所未有的视图。这些横截面将应用于飓风生命周期的几个阶段，以确定内核风和热力学结构如何随着风暴增强或减弱而变化。通过这些分析，首席研究员将能够确定流入眼壁的质量和水分，以及流入层在哪里获得产生和维持飓风循环所需的能量。多个横截面将允许检测由于环境差异或雨带以及它们如何影响飓风强度而导致的流动中的中尺度不对称性。 导出的场将作为飓风数值模拟的基准。人们认为，存在于眼睛下部的高能空气会增加眼壁的不稳定性，并导致强度水平超过最大潜在强度理论预测的强度水平。通过在风暴生命周期中废弃的 GPS 探空仪观察到的眼部结构与飞机在眼壁中进行的现场测量进行比较，将加深对下眼部热力学如何影响强度的理解。在飓风登陆前一两天从高空 NOAA G-IV 和 WP-3D 部署的 GPS 探空仪将用于识别风暴近海时水平风的不稳定性和垂直切变。这些关键指数将与登陆时和登陆后在循环中发射的国家气象局罗温探空仪诊断的情况进行比较。目的是确定哪些飓风会产生大量龙卷风，以及登陆时风场和热力场如何演变。这是 G-IV 部署的 GPS 探空仪首次用于飓风路径改善以外的工作。该研究的更广泛影响包括开发有效的采样策略，以更好地探测正在发生强度变化的飓风的内核，从而改进强度预测，从而为美国带来巨大的安全和经济效益。该提案解决了 NSF 国家科学委员会、NOAA 科学咨询委员会、美国气象学会和美国天气研究计划说明书开发团队确定的问题。这项工作的教育效益包括研究生的培训以及本科生和研究生飓风课程的持续开发。这项工作加强了夏威夷大学和 NOAA 飓风研究部门之间的合作关系。