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.

主要研究员将利用1997年以来从诺阿、国家科学基金会和美国航天局赞助的飞机上部署的全球定位系统探测仪的大量档案资料，研究飓风强度的变化。这些探测仪将与飞机雷达和飞机现场传感器结合起来，用于在飓风相当长的一段时间内采样的几次飓风。全球定位系统探测仪提供从飞机高度以下到飓风内核海面（风眼至300公里径向距离）的风和热力学数据。鉴于研究使命的高成本，利用由美国海洋和大气管理局飓风研究司维护的全球定位系统探空仪档案是飓风强度研究的一种经济方法。主要研究者开发了一种三次样条分析，可以有效地构建横截面（例如，入流距离-高度、方位角-高度和径向距离-高度），提供了对流层下部和低空入流的前所未有的视图。这些横截面将应用于飓风生命的几个阶段，以确定内核风和热力学结构如何随着风暴的增强或减弱而变化。通过这些分析，首席研究员将能够确定眼墙的质量和水分流入，以及流入层获得创建和维持飓风环流所需的能量。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中尺度不对称性。 导出的场将作为飓风数值模拟的基准。存在于眼下部的高能空气被认为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的预测。在整个风暴的生命和飞机在眼墙的现场测量丢弃的GPS探空仪所看到的眼结构之间的比较将增加对下眼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探测仪将用于确定风暴在近海时水平风的不稳定性和垂直切变。这些关键指数将与国家气象局在登陆时和登陆后在环流中发射的rawinsondes诊断的条件进行比较。其目的是确定哪些飓风会产生大量的龙卷风，以及登陆时风场和热力场如何演变。这是第一次从G-IV部署的GPS探测器将用于飓风轨迹改进以外的工作。该研究的更广泛影响包括制定有效的采样策略，以更好地探测经历强度变化的飓风的内核，从而改善对强度的预测，为美国带来重大的安全和经济利益。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培训研究生和继续为本科生和研究生开设飓风课程。这项工作加强了夏威夷大学和NOAA飓风研究部门之间的伙伴关系。