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

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，这反映在较差的预测上。最近的结果表明，非洲东风波在大西洋盆地形成的路径受到东移对流耦合开尔文波传播的影响。然而，缺乏对这些相互作用的过程和可预测性的量化评估。迈阿密大学和奥尔巴尼大学的这项合作研究项目寻求提供这样一个定量评估，并寻求对热带风暴研究中一个悬而未决的问题更明确的答案：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不成因有关的物理机制假说。第二阶段将使用20年来存档的集合预报数据，在这些物理机制的背景下调查和量化可预测性。第三阶段将把这些想法延长到1-2周，考虑到马登-朱利安涛动、厄尔尼诺和南方涛动的作用。该项目的一个新方面是认识到有必要考虑到对流耦合开尔文波的幅度和非洲东风波结构对成因的有利程度。第二个新的发展是使用集合预报来推进可预报的边界，确定复杂相互作用的可预报程度到1-2周，并将可预报的思想与主导的物理机制和大尺度流系相联系。这项研究将提供定量信息来支持热带预报员。这项研究还将通过促进我们对科学和可预测性的理解，超越传统的天气时间尺度，弥合天气和亚季节预报社区之间的差距，这是国家和全球公认的优先事项。这将导致确定对热带气旋活动和成因的预测技能高低的区域，从而为预报员和最终根据潜在的热带气旋威胁采取行动的决策者提供信息。这项研究的副产品将是向业务建模中心提供的关于其集合预报的优点和缺点的反馈。在这项研究中开发的诊断工具将与研究界共享。该项目还将通过资助两名学生进行博士研究，以及推进热带气象学新的本科生和研究生课程，来促进科学、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能够参观各自城市的气象中心和设施。开展本科生荣誉论文项目。作为该项目的一部分，将继续开展几项与热带气旋有关的外展活动，旨在提高决策者、媒体和公众的科学素养。这一奖项反映了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。

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.