Date of Award
8-16-2024
Document Type
Open Access Dissertation
Department
Marine Science
First Advisor
Michael Bizimis
Abstract
Coherent vortices known as eddies are ubiquitous throughout the world’s oceans and are responsible for modulating regional climates via the transfer of heat, momentum, and salt. Two regions where eddies are particularly prominent are the Arabian Sea (AS) and the Gulf of Mexico (GoM). This dissertation advances the study of eddies in these regions by developing and employing new techniques in conjunction with remotely sensed data and high-resolution ocean models. These models focus particularly on lesser-studied eddy components at the subsurface and the submesoscale (below 25 km in radius).
The first component of this dissertation focuses on the Lakshadweep High (LH), a climatological eddy in the AS. Using an automatic eddy tracking algorithm, the entire life cycle of the LH is described for the first time, including its previously unresolved propagation to the Somali Current. There, the LH negatively influences the eddy kinetic energy of the current by inhibiting the formation of a cyclonic eddy after the onset of the southwest monsoon.
Refocusing on the subsurface component of the eddy field in the AS, the second part of this work is the development of a novel eddy tracking algorithm using the rescaled Potential Vorticity (PV) to detect eddies in ocean models. Compared to its alternatives, the PV algorithm provides superior performance in terms of eddy detection. This algorithm illuminates a previously unknown eddy in the southern AS near the Chagos Archipelago that mixes Red Sea Water with Antarctic Intermediate Water and downwells the result.
The final component of this dissertation moves to the GoM, where a 1/48° grid resolution simulation is used with a custom-designed spatial filtering process to isolate the small-scale component of the eddy field. This submesoscale eddy field induces variability in temperature, salinity, and eddy kinetic energy in the overlying mesoscale eddy field. Additionally, the presence of submesoscale eddy-like features predicts eddy dissipation and Loop Current Eddy (LCE) separation. The techniques and results presented in this dissertation combine to elucidate previously unresolved eddy dynamics in culturally important regions, providing the tools for researchers to do the same in other regions in the future.
Rights
© 2024, Paul Andrew Ernst
Recommended Citation
Ernst, P. A.(2024). New Techniques for Studying Ocean Eddy Dynamics in the Arabian Sea and the Gulf of Mexico. (Doctoral dissertation). Retrieved from https://scholarcommons.sc.edu/etd/7773