ORCID

https://orcid.org/0009-0007-5400-9296

Date of Award

Summer 2026

Language

English

Embargo Period

7-27-2026

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

Brian Tang

Second Advisor

Kristen Corbosiero

Committee Members

Brian Tang, Kristen Corbosiero

Keywords

Tropical Cyclones, Satellite, Observations

Subject Categories

Atmospheric Sciences | Meteorology

Abstract

Tropical cyclone (TC) intensity change in moderate vertical wind shear (VWS) is difficult to predict. Specifically, ventilation, the intrusion of dry and/or cool (i.e., low equivalent potential temperature (theta-e) air inside the TC, can have differing effects on TCs. Downdraft ventilation is the downward transport of below-mean  theta-e air by downdrafts, and radial ventilation is the inward transport of below-mean theta-e air by storm-relative radial winds. If this low theta-e air is able to get ingested by updrafts, it can result in a reduction of convection in the TC, thereby reducing intensity. Although most studies of ventilation have been conducted using numerical simulations, recent work has begun to look at ventilation through observations. This study will look at both radial and downdraft ventilation from two previous storms, hurricanes Earl (2010) and Edouard (2014), that had high-quality data coverage.

This study employs observations from a variety of different sources, including dropsondes, satellite imagery, radars from both the ground and onboard aircraft, reanalysis, and numerical simulations. One satellite source, not extensively used in previous TC applications, that this study uses is the 183.31-GHz microwave satellite band, which provides information regarding water vapor at different atmospheric levels in the near-environment surrounding the TC.

Results from Hurricane Earl (2010) show ventilation pathways active during the storm’s weakening. Downdraft ventilation was active in the storm’s downshear-left quadrant, consistent with previous work. Additionally, radial ventilation was large between 300–600 hPa in the upshear-left quadrant, with strong radial inflow bringing in lower theta-e air. However, the degree to which downdraft ventilation, in particular, affected Earl’s intensity may have been limited due to high surface enthalpy fluxes on the left-of-shear side of the storm due to the influence of the Gulf Stream, which, in turn, can cause quick recovery of the low- air.

Two separate periods were analyzed in Hurricane Edouard (2014), one during the storm’s intensification phase and another during the storm’s weakening phase. During the storm’s intensification phase, ventilation was limited despite the proximity of an upper-level trough and low- air. The one exception was in the upshear-right quadrant, where some observations of downdraft and radial ventilation occurred within 100 km from the TC center. However, these ventilation observations were isolated occurrences and not representative of dropsondes in the upshear-right quadrant as a whole. During the storm’s weakening phase, observations of downdraft and radial ventilation became more widespread in the upshear-right and downshear-left quadrants. Additionally, surface enthalpy fluxes decreased, suggesting that ventilation could be more detrimental to the TC.

License

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

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