Large-Scale Influences on Tropical Cyclogenesis

对热带气旋发生的大规模影响

• 批准号: 0201752
• 负责人: John Molinari
• 金额: $ 40.67万
• 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: 2002
• 资助国家: 美国
• 起止时间: 2002-07-15 至 2005-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0201752&HistoricalAwards=false
• 关键词: Large; Scale; Influences; Tropical; Cyclogenesis

The objective of this project is to study tropical cyclongenesis and, in particular, what roles different environmental flows play in it. Three research avenues will be pursued. The first one is to examine tropical cyclogenesis in the eastern Pacific using data from the East Pacific Investigation of Climate Processes (EPIC) experiment in which the PI actively participated and the Outgoing Long-wave Radiation (OLR) data from NOAA. The focus will be the relationship between the intertropical convergence zone (ITCZ) and easterly waves before tropical cyclones form. For the second avenue, the PI will attempt to reconcile two paradigms of tropical cyclogenesis in the western Pacific and Gulf of Mexico, namely, the spin-up of vortices in the monsoon trough versus easterly waves interacting with the Madden Julian Oscillation (MJO) as pre-cursors to cyclogenesis. The working hypothesis is that tropical cyclogenesis often occurs under the following circumstances: 1) an active MJO producing a strong monsoon trough with westerlies to its south and 2) upstream waves reach the active MJO, grow in amplitude, and are ultimately the locus of depression formation. In this way, the MJO, monsoon trough, and upstream waves all participate and interact in cyclone formation. The third avenue is to conduct numerical simulations using shallow water and barotropic models to test the working hypothesis, using both idealized background states and those extracted from observational data with MJO signals.Tropical cyclogenesis remains one of the most challenging tasks in weather prediction. Increasing the understanding of how environmental flows affect genesis is important both from the prediction and modeling perspectives. The planned research has the potential of shedding some light in this area and the research will provide good opportunities for graduate studies.

该项目的目标是研究热带气旋的发生，特别是不同的环境流在其中发挥的作用。 将采取三种研究途径。 第一个是利用 PI 积极参与的东太平洋气候过程调查 (EPIC) 实验的数据和来自 NOAA 的传出长波辐射 (OLR) 数据来研究东太平洋的热带气旋发生。 重点是热带气旋形成前热带辐合带（ITCZ）与东风波之间的关系。 对于第二条途径，PI将尝试调和西太平洋和墨西哥湾热带气旋发生的两种范式，即季风槽中涡旋的旋转与作为气旋发生前兆的马登朱利安涛动（MJO）相互作用的东风波。 工作假设是，热带气旋通常在以下情况下发生：1）活跃的MJO产生强烈的季风槽，其南部有西风带；2）上游波浪到达活跃的MJO，振幅增加，并最终成为低压形成的场所。 这样，MJO、季风槽和上游波浪都参与并相互作用形成气旋。 第三种途径是使用浅水和正压模型进行数值模拟，以测试工作假设，同时使用理想化背景状态和从 MJO 信号观测数据中提取的状态。热带气旋形成仍然是天气预报中最具挑战性的任务之一。 从预测和建模的角度来看，增加对环境流如何影响起源的理解都很重要。 计划中的研究有可能为该领域带来一些启示，并且该研究将为研究生学习提供良好的机会。