Collaborative Research: Environmental Control of Tropical Cyclone Activity

合作研究：热带气旋活动的环境控制

• 批准号: 0850639
• 负责人: Kerry Emanuel
• 金额: $ 39.98万
• 依托单位: Massachusetts Institute of Technology
• 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: 2009-06-15 至 2013-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0850639&HistoricalAwards=false
• 关键词: Collaborative; Research; Environmental; Control; Tropical

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Recent research has established that much and perhaps most of the interannual to interdecadal variation of tropical cyclone activity integrated over ocean basins is controlled by the large-scale atmospheric and oceanic environment in which the storms develop. Statistical and model-based hindcasts of Atlantic tropical cyclone activity capture as much as 65% of the interannual variance of tropical cyclone frequency, despite taking little or no account of potential initiating disturbances, such as African easterly waves. These same techniques, however, produce greatly divergent results when applied to global warming scenarios. This highlights the need for a better physical understanding of the link between tropical cyclones and climate. This project will seek such an understanding using several different, but complementary, approaches. The first is an investigation, using a cloud-scale model, of the formation, or failure to form, of tropical cyclones from seed cyclonic disturbances in large-scale environments of radiative-convective equilibrium with shear. Previous results with this method will be extended to a wider range of wind profiles that include speed and directional shear, allowing for a careful study of cyclogenesis (or failure) in realistic environments that still can be systematically adjusted and compared. A second approach builds on the success of the Genesis Potential Index (GPI), which, when applied to historical data, has been shown to explain much of the interannual variance and long-term trend in tropical cyclone activity. Here it will be used to understand the physical factors responsible for predicted variations in the GPI in climate models simulating the response to global warming. The index will be improved using results from the cloud-resolving model simulations. Finally, one or two cases of genesis in the cloud-resolving model will be analyzed in some depth, in an attempt to test the hypothesis that tropical cyclones can develop only in mesoscale patches that are nearly saturated through most of the troposphere.Broader impacts are in advancing understanding of the relationships between tropical climate and tropical cyclone activity. This could lead to better and more useful assessments of how tropical cyclone activity may or may not change with a changing climate. This work may also yield a more fundamental understanding of the process of tropical cyclone formation, ultimately leading to better short-term forecasts of the formation of tropical depressions and storms. The project will support the training of a young scientist or post-doc and a graduate student and will contribute to further development of a flexible idealized hurricane modeling system based on the widely-used Weather Research and Forecasting (WRF) model.

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。最近的研究表明，海洋盆地上空热带气旋活动的年际至年代际变化很大程度上是由风暴发展的大尺度大气和海洋环境控制的。大西洋热带气旋活动的统计和基于模型的后报捕获了热带气旋频率年际变化的65%，尽管很少或根本没有考虑潜在的初始扰动，如非洲东风波。然而，这些相同的技术在应用于全球变暖情景时会产生非常不同的结果。这突出表明需要更好地从物理上了解热带气旋与气候之间的联系。本项目将使用几种不同但互补的方法来寻求这种理解。第一个是调查，使用云尺度模式，从种子气旋扰动的热带气旋的形成，或未能形成，在大尺度环境中的辐射对流平衡与剪切。以前的结果与这种方法将被扩展到更广泛的风廓线，包括速度和方向性切变，允许在现实环境中，仍然可以系统地调整和比较的气旋生成（或故障）的仔细研究。第二种方法建立在成因潜力指数（GPI）的成功基础上，该指数应用于历史数据时，已被证明可以解释热带气旋活动的大部分年际变化和长期趋势。在这里，它将被用来了解物理因素负责预测的变化，在气候模型模拟全球变暖的响应。该指数将使用云解析模型模拟的结果进行改进。最后，将对云解析模式中的一两个成因案例进行深入分析，以验证热带气旋只能在对流层大部分区域接近饱和的中尺度斑块中发展的假设。更广泛的影响是促进对热带气候和热带气旋活动之间关系的理解。这可能导致更好和更有用的评估热带气旋活动如何可能会或可能不会随着气候变化而变化。这项工作还可能对热带气旋的形成过程产生更基本的了解，最终导致对热带低气压和风暴形成的更好的短期预报。该项目将支持培训一名青年科学家或博士后和一名研究生，并将有助于在广泛使用的天气研究和预报模型的基础上进一步开发一个灵活的理想化飓风建模系统。