AGS-PRF: Organization of Tropical Convection in Numerical Model Simulations: Self-Aggregation and Tropical Cyclogenesis

热带云和雷暴，也就是所谓的热带对流，经常被组织成包含许多单体的星团。这些团簇在影响降水分布和局部温度以及大尺度风和湿度模式方面发挥着重要作用。先前的数值模拟研究表明，对流具有通过更广泛的环境与对流之间的相互作用进行自组织的能力，这一过程被称为“自聚集”。在这项工作中，研究人员将把自聚集的概念应用于热带气旋的形成。该项目将以建模为基础，在理想和现实模式设置中模拟热带对流。这项工作的成功完成将有助于提高对热带气旋形成的认识，并有可能作出更好的预报。这项工作还将为气候模型提供更准确的热带对流表征。该研究人员计划通过参与各种公共宣传活动，为提高公众对科学的理解做出贡献。该项目的主要目的是确定对流自聚集在热带气旋形成中的作用。解决三个主要问题。研究人员将首先对自发热带气旋形成进行反馈分析。这包括使用大气模拟系统（SAM）进行模拟。研究人员将允许环流自发发展，而不是对模拟的对流施加外部强迫。反馈分析将使研究人员能够直接比较热带气旋的自发形成与非旋转自聚集群集的发展。研究计划的第二步是将上述云分辨模拟中的成因过程与气候模型中的过程进行比较。研究计划的最后一步将是通过强迫波扰动通过模式域并包括背景切变来研究更现实的云解析模拟中的对流组织机制。

Tropical clouds and thunderstorms, known as tropical convection, are often organized into clusters containing many individual cells. These clusters play a significant role in impacting precipitation distribution and local temperatures, as well as large-scale wind and moisture patterns. Prior numerical modeling studies have shown that convection has the ability to self-organize through interactions between the broader environment and the convection, a process known as "self-aggregation". In this work, the researcher will apply the concept of self-aggregation to the formation of tropical cyclones. The project will be modeling-based, with simulations of tropical convection in both idealized and realistic model setups. A successful completion of the work would lead to improved understanding of the formation of tropical cyclones and the potential for better forecasts. The work will also benefit climate models by providing a more accurate representation of tropical convection. The researcher plans to contribute to increasing public understanding of science by participating in a variety of public outreach efforts.The main objective of the project is to determine the role of convective self-aggregation in tropical cyclogenesis. Three main tasks will be addressed. The researcher will first conduct a feedback analysis of spontaneous tropical cyclogenesis. This involves simulations using the System for Atmospheric Modeling (SAM). Rather than impose an external forcing on the modeled convection, the researcher will let the circulation be allowed to develop spontaneously. A feedback analysis will allow the researcher to directly compare the spontaneous genesis of a tropical cyclone to the development of a non-rotating self-aggregated cluster. The second step of the research plan will be to compare the genesis processes in the cloud-resolving simulations above to those processes in climate models. The final step of the research plan will be to study the mechanisms of convective organization in a more realistic cloud resolving simulation by forcing a wave disturbance through the model domain and by including background shear.