Theses and Dissertations

ORCID

https://orcid.org/0009-0004-2017-5454

Advisor

Rudzin Schwing, Johna

Committee Member

Richter, David

Committee Member

Dyer, Jamie

Committee Member

Mercer, Andrew

Date of Degree

5-15-2026

Original embargo terms

Visible MSU Only 6 months

Document Type

Dissertation - Campus Access Only

Major

Earth and Atmospheric Sciences

Degree Name

Doctor of Philosophy (Ph.D.)

College

College of Arts and Sciences

Department

Department of Geosciences

Abstract

This research quantifies variability in surface drag coefficient (Cd) estimates stemming from varying location across a tropical cyclone (TC), the influence of TC forward speed, and the degree of atmospheric stability. Data are obtained from atmospheric dropsondes deployed in Atlantic TCs between 1996 and 2021, and Cd is estimated using the flux profile method. First, the spatial variability of Cd estimates with respect to distance and direction from the TC center is investigated to infer the role of varying wave characteristics across the storm on the Cd. Second, Cd estimates for TCs moving at various forward speeds are compared to determine if and how forward speed influences Cd. This section also considers how the TC forward speed may influence Cd differently on the right versus left side of the storm. Lastly, since many studies assume a neutrally stable boundary layer which may not be applicable in a hurricane, the role of stability on Cd is investigated by comparing Cd estimates for dropsondes located in stable and unstable environments within the TC. Specifically, this section compares Cd estimates between environments with different degrees of stability with and without utilizing a stability correction term to better understand the circumstances under which such a term is necessary. Furthermore, this chapter considers where within a storm stable and unstable regimes are most common and how the effect of stability may be reflected in the Cd estimates presented in the quadrant analysis. Results show that Cd estimates vary spatially and between environments, but that most variability in Cd is related to varying degrees of wind-wave alignment across TCs. Results are limited primarily by sample size and the lack of direct wave and ocean-atmosphere flux observations in extreme environments, which is a potential focus of future work.

Sponsorship (Optional)

This work is supported by the Office of Naval Research (ONR) grant #N00014-22-5-F007 awarded to my advisor, Johna Rudzin.

Download

Share

COinS