Subtropical Gyres: Formation, Dynamics, and Climatology

这是一个研究副热带气旋的项目，副热带气旋是夏季北部，特别是北太平洋西部，出现在北纬12-30度之间的低对流层气旋。它们比热带气旋(TC)大，有时含有热带气旋，在它们内部形成热带气旋，并在它们周围气旋传播。这项工作将调查环流的起源、气候学、结构和动力学，并研究它们的时空分布及其对降水和TC生成的贡献。该项目首先确定一套适当的标准来定义副热带气旋，以便可以使用自动化过程来创建它们的记录，用于确定它们的空间和季节分布、典型的大小和持续时间以及与厄尔尼诺事件和马登-朱利安振荡有关的变化。接下来，将重点研究副热带气旋的结构、演变和动力学。除了观测记录，这项研究还将使用天气研究和预报(WRF)模式的模拟来检验各种物理机制对涡旋演变的贡献，包括地面风对与涡旋内对流相关的非绝热加热的响应，以及随后在涡旋西侧地面热交换的增强。鉴于涡旋与TC形成的联系，对副热带涡旋的研究具有社会价值。副热带气旋内形成的台风对东亚和东南亚沿海地区构成威胁，在该奖项下开展的工作可能有助于更好地了解和预测这些风暴。此外，该项目还支持一名研究生，从而有助于该科学领域的下一代研究人员。

This is a project to study subtropical gyres, which are lower-tropospheric cyclones occurring between 12N and 30N in northern summer, especially in the western North Pacific. They are larger than tropical cyclones (TCs), and sometimes contain TCs that form within them and propagate cyclonically around them. The work will investigate the origin, climatology, structure, and dynamics of the gyres, and study their spatial and temporal distribution and their contribution to precipitation and TC genesis. The project begins by determining an appropriate set of criteria to define subtropical gyres, so that an automated process can be used to create a record of them, to be used to determine their spatial and seasonal distribution, typical size and duration, and variations associated with El Nino and events and the Madden-Julian Oscillation. Next, the research will focus on the structure, evolution, and dynamics of subtropical gyres. In addition to the observational record, the research will use simulations from the Weather Research and Forecasting (WRF) model to examine the contributions of various physical mechanisms to gyre evolution, including the surface wind response to diabatic heating associated with convection within the gyre, and the subsequent enhancement of surface heat exchange on the western side of the gyre.Research on subtropical gyres has societal value given the association of the gyres with TC formation. Typhoons forming within subtropical gyres pose a threat to the coastal regions of East and Southeast Asia, and the work performed under this award may contribute to better understanding and prediction of these storms. In addition, the project supports a graduate student and thus contributes to the next generation of researchers in this scientific area.