Collaborative Research: Mechanisms and Predictability of Interactions between Convectively Coupled Kelvin Waves and African Easterly Waves Leading to Tropical Cyclogenesis

合作研究：对流耦合开尔文波与非洲东风波相互作用导致热带气旋的机制和可预测性

• 批准号: 1747781
• 负责人: Sharanya Majumdar
• 金额: $ 38.34万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-03-15 至 2024-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1747781&HistoricalAwards=false
• 关键词: Collaborative; Research; Mechanisms; Predictability; Interactions

Tropical storms and hurricanes in the Atlantic basin impact lives, the economy, and society. While the ability to forecast the track of tropical cyclones has improved, gaps remain in the knowledge and understanding of their formation or genesis, which is reflected in poorer forecasts. Recent results suggest that the African easterly waves pathway to genesis in the Atlantic Basin is influenced by the passage of eastward-moving convectively coupled Kelvin Waves. However, a quantitative assessment of the processes and predictability of these interactions is lacking. This collaborative research project between the University of Miami and the University at Albany seeks to provide such a quantitative assessment and to seek a more definite answer to an outstanding question in the tropical storm research: "why do some African easterly waves develop into Tropical Cyclone (TC) and others do not?". The project is divided into three phases. The first phase will use three decades of observational and reanalysis data to test hypotheses on the physical mechanisms related to the attribution of genesis or lack of genesis to convectively coupled Kelvin Waves, on time scales of 1-3 days. The second phase will use two decades of archived ensemble forecast data to investigate and quantify the predictability in the context of these physical mechanisms. The third phase will extend these ideas out to 1-2 weeks, accounting for the roles of the Madden-Julian Oscillation and El Niño and the Southern Oscillation. One novel aspect of the project is the awareness of the need to take account of convectively coupled Kelvin Wave amplitude and favorability of African Easterly Wave structures for genesis. A second novel development is to use ensemble forecasts to push the boundaries of predictability, in identifying the extent to which the complex interactions are predictable out to 1-2 weeks, and connecting the predictability ideas to the governing physical mechanisms and large-scale flow regimes.The research will provide quantitative information to support tropical forecasters. The research will also bridge the gap between the weather and subseasonal prediction communities by advancing our understanding of science and predictability beyond traditional weather time scales, which is recognized nationally and globally as a priority. This will lead to the identification of regimes where predictive skill of genesis and tropical cyclone activity is high or low, thereby providing information to forecasters and ultimately the decision makers who take actions based on a potential tropical cyclone threat. A by-product of the research will be the feedback provided to operational modeling centers on strengths and weaknesses of their ensemble forecasts. Diagnostic tools developed in this research will be shared with the research community. The project will also advance Science, Technology, Engineering and Mathematics education by funding two students to pursue doctoral research, and in advancing new undergraduate and graduate courses on tropical meteorology. An annual exchange between Miami and Albany will enable the students to visit meteorological centers and facilities in their reciprocal cities. Undergraduate Honors thesis projects will be developed. Several outreach activities related to tropical cyclones, aimed at increasing scientific literacy among decision-makers, the media and public will be continued as part of this project.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

大西洋盆地的热带风暴和飓风影响着人们的生活、经济和社会。虽然预测热带气旋路径的能力有所提高，但在对其形成或成因的认识和理解方面仍然存在差距，这反映在较差的预报中。最近的研究结果表明，非洲东风波在大西洋盆地的形成路径受到向东移动的对流耦合开尔文波通道的影响。然而，缺乏对这些相互作用的过程和可预测性的定量评估。迈阿密大学和奥尔巴尼大学的合作研究项目旨在提供这样的定量评估，并为热带风暴研究中的一个突出问题寻求更明确的答案：“为什么一些非洲东风波发展成热带气旋（TC）而另一些则没有？”该项目分为三个阶段。第一阶段将使用三十年的观测和再分析数据，在1-3天的时间尺度上，测试与对流耦合开尔文波的成因或缺乏成因相关的物理机制的假设。第二阶段将使用二十年来存档的整体预测数据来调查和量化这些物理机制背景下的可预测性。第三阶段将把这些想法延长1-2周，考虑到马登-朱利安涛动、厄尔尼诺Niño和南方涛动的作用。该项目的一个新颖方面是认识到需要考虑对流耦合开尔文波振幅和非洲东部波结构对成因的有利性。第二个新颖的发展是使用集合预测来突破可预测性的界限，在确定复杂的相互作用可预测到1-2周的程度，并将可预测性的想法与控制物理机制和大规模流动状态联系起来。这项研究将为热带预报员提供定量信息。该研究还将通过提高我们对传统天气时间尺度之外的科学和可预测性的理解，弥合天气和亚季节预测社区之间的差距，这是国家和全球公认的优先事项。这将有助于确定对热带气旋形成和活动的预测能力高或低的地区，从而为预报员提供信息，并最终为根据潜在热带气旋威胁采取行动的决策者提供信息。该研究的一个副产品将是提供给业务建模中心的关于其集合预测的优缺点的反馈。本研究开发的诊断工具将与研究界共享。该项目还将资助两名学生进行博士研究，并推进新的热带气象学本科和研究生课程，从而推进科学、技术、工程和数学教育。迈阿密和奥尔巴尼之间的年度交流将使学生们能够参观各自城市的气象中心和设施。将开发本科荣誉论文项目。若干与热带气旋有关的外联活动，旨在提高决策者、媒体和公众的科学素养，将作为这个项目的一部分继续进行。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

The Influence of Convectively Coupled Kelvin Waves on African Easterly Waves in a Wave-Following Framework

波浪跟踪框架中对流耦合开尔文波对非洲东风波的影响

• DOI: 10.1175/mwr-d-21-0321.1
• 发表时间: 2022
• 期刊: Monthly Weather Review
• 影响因子: 3.2
• 作者: Lawton, Quinton A.;Majumdar, Sharanya J.;Dotterer, Krista;Thorncroft, Christopher;Schreck, Carl J.
• 通讯作者: Schreck, Carl J.