Date of Award

Summer 2025

Language

English

Embargo Period

7-26-2025

Document Type

Master's Thesis

Degree Name

Master of Science (MS)

College/School/Department

Department of Atmospheric and Environmental Sciences

Program

Atmospheric Science

First Advisor

Kristen Corbosiero

Second Advisor

Brian Tang

Keywords

Tropical cyclone, vorticity budget, turbulent kinetic energy budget, misoscale vortices, large eddy simulation

Subject Categories

Atmospheric Sciences

Abstract

Since the late 1980s, there have been numerous observations of extreme updrafts, gusts, and small-scale rotation in the eyewall of tropical cyclones (TCs). Research aircraft, dropsondes, and, more recently, mobile radars have collected these observations, most often from within the boundary layer. Previous studies have documented dropsondes associated with extreme gusts and updrafts, while others have discussed specific incidents of misoscale features in tropical cyclones. Several high-resolution numerical simulations of TCs have documented similar features. This study uses one such simulation from Worsnop et al. (2017). A small but intense tropical cyclone in a quiescent environment is simulated.

This simulation produces misoscale features characterized by high vertical vorticity in the lowest 300 m. These features occur throughout the domain, but are strongest within the eyewall, amid the strongest radial and tangential wind gradients. A selection of eight features that meet both wind speed and vertical vorticity intensity criteria, and are from within the eyewall region, are composited during growth, maximum intensity, and decaying stages. These features intensity rapidly due to vortex stretching in the lowest 50 m above the surface. They exhibit negative pressure perturbations associated with the strong vertical vorticity. The features also have high turbulent kinetic energy (TKE). The dominant terms in the TKE budget for these features are the radial and tangential elongation terms, and all eight of the features used in the composite lie along the largest azimuthally averaged radial wind gradient. This study presents an analysis of the characteristics of these features, a vertical vorticity budget, a pressure decomposition, and a TKE budget of the composite at growing, maximum intensity, and decaying time frames.

License

This work is licensed under the University at Albany Standard Author Agreement.

Download

Share

COinS