Role of Intense Convection in Sheared Tropical Cyclones

强对流在热带气旋切变中的作用

• 批准号: 0855718
• 负责人: John Molinari
• 金额: $ 44.33万
• 依托单位: SUNY at Albany
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0855718&HistoricalAwards=false
• 关键词: Role; Intense; Convection; Sheared; Tropical

This project has three parts. First, a composite study will be conducted of the azimuthal helicity distribution in a group of tropical cyclones with respect to ambient vertical wind shear. A previous study of Hurricane Bonnie showed an enormous azimuthal asymmetry in helicity, with large helicity and intense supercell-like storms in the downshear direction. The goal is to examine the robustness of these results over a wide range of storms. Second, a detailed study will be carried out concerning the evolution of Hurricane Bonnie using an extensive set of airborne meteorological and radar data, and dropsonde observations, obtained during that storm. The goal is to understand how the storm maintained its intensity in the presence of strong ambient shear. Finally, the role of the helicity distribution on the formation and downshear re-formation of tropical storms will be examined. Radar observations will be obtained for a group of near-coastal tropical cyclones within range of continuous land-based radar. Tropical Storm Gabrielle (2001) will be one storm in the study. The goal is to examine the structure and evolution of individual thunderstorm cells within the cyclone in the presence of large helicity and how such cells influence the larger-scale cyclone circulation.Broader impacts include the training of graduate students, support for graduate students to attend conferences and present their work, and dissemination of results in the refereed literature and at conferences. The research results will contribute to a greater understanding and better prediction of hurricanes. Project scientists and students will also give talks on hurricanes to lay groups as part of outreach efforts.

该项目有三个部分。首先，将对一组热带气旋相对于环境垂直风切变的方位角螺旋度分布进行综合研究。之前对飓风邦尼的研究显示，螺旋度在方位角上存在巨大的不对称性，在下切变方向上存在大螺旋度和强烈的超级单体风暴。我们的目标是检查这些结果在大范围风暴的鲁棒性。第二，将利用在邦尼飓风期间获得的一套广泛的空中气象和雷达数据以及投下式探空仪观测结果，对该风暴的演变进行详细研究。目标是了解风暴如何在强环境切变存在的情况下保持其强度。最后，将研究螺旋度分布对热带风暴的形成和下切再形成的作用。在陆基连续雷达的观测范围内，将获得一组近岸热带气旋的雷达观测结果。热带风暴加布里埃尔（2001年）将是研究中的一个风暴。其目的是研究在大螺旋度情况下气旋内单个雷暴单体的结构和演变，以及这些单体如何影响大尺度气旋环流，更广泛的影响包括培训研究生，支持研究生参加会议并介绍他们的工作，以及在参考文献和会议上传播结果。研究结果将有助于更好地了解和更好地预测飓风。作为推广工作的一部分，项目科学家和学生还将为非专业团体举办飓风讲座。