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.
