Large-Scale Influences on Tropical Cyclogenesis

该项目将研究“热带气旋归因”，以确定一个季节中每个热带气旋发展的主要预先存在的扰动。研究人员将(i)开发并应用一种方法，将热带气旋形成归因于一种或多种类型的赤道波；（ii）处理现有文献中关于热带气旋前体的各种不同观点；（iii）尝试将传统的热带气象实践与利用赤道波理论的替代框架结合起来。最后一部分工作的目标是将研究界的一些想法转移到实际的热带气旋预报界。在之前的NSF支持下，研究人员已经研究了混合罗斯比重力、赤道罗斯比、东风波和马登-朱利安涛动对热带气旋形成的作用。在这个项目中，他们将研究“季风环流”内热带气旋的形成。这些是广泛的副热带低气压区，经常产生多个热带气旋。这两部分工作的最终目标是建立一种统一的方法来理解热带气旋的前驱扰动。该项目的更广泛影响包括：(i)将依赖卫星图像的业务预报方法与一些更好地定义前驱扰动的新理论方法合并的潜力，最终改进5-10天时间尺度上的飓风形成预报；（ii）研究生培训；（iii）在会议、讲习班和参考文献中广泛传播结果和发现。作为拓展工作的一部分，首席研究员还将向非专业团体发表关于飓风的演讲。

This project will examine "tropical cyclone attribution" to identify the primary pre-existing disturbance(s) out of which each tropical cyclone in a season develops. The investigators will (i) develop and apply a means of attributing tropical cyclogenesis to one or more types of equatorial waves; (ii) address the wildly divergent views of existing papers in the literature on tropical cyclone pre-cursors; and (iii) attempt to merge traditional tropical meteorology practice with an alternative framework that makes use of equatorial wave theory. The goal of the last part of the work is to move some ideas from the research community into the operational tropical cyclone forecast community.The investigators have examined the role of mixed Rossby-gravity, equatorial Rossby, easterly waves and the Madden-Julian Oscillation on tropical cyclogenesis in their previous NSF support. In this project they will study tropical cyclone formation within "monsoon gyres". These are broad subtropical low pressure areas that often produce multiple tropical cyclones. The ultimate goal of the two parts of this work is to develop a unified approach to understanding the precursor disturbances for tropical cyclones. The broader impacts of this project include (i) the potential in merging operational forecast methods that rely on satellite images with some new theoretical approaches that better define the precursor disturbances, to ultimately improve the forecasts of hurricane formation on a time scale of 5-10 days, (ii) the training of graduate students and (iii) wide dissemination of results and findings in conferences, workshops, and the refereed literature. The principal investigator will also give talks on hurricanes to lay groups as part of outreach efforts.