Date of Award

Summer 2017

Document Type


Degree Name

Doctor of Philosophy (PhD)


Chemistry and Biochemistry

Committee Director

Peter Bernath

Committee Member

Ken Brown

Committee Member

John Cooper

Committee Member

Charles Sukenik

Committee Member

John Donat


Increases in greenhouse gas concentrations in the atmosphere are the major driver of climate change. Quantifying the sources and sinks of these gases is a major focus of research. Measuring isotopologues, or molecules that differ in isotopic composition, is one useful way of constraining the budget of a molecule as they are highly sensitive to different sources and sinks. However, measurements above the surface have been restricted to a few locations and have only reached the lower stratosphere. Satellite-based remote sensing can achieve nearly global measurement coverage, but so far no satellites have measured isotopologues.

Presented here are measurements of isotopologues of CH4, CO, CO2, and N2O in the stratosphere and mesosphere collected using the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS). These measurements are complemented by model runs using the Whole Atmosphere Community Climate Model (WACCM). Both data sets show the strong influence of transport in the upper atmosphere on the isotopic distribution of these molecules. In addition, WACCM accurately calculates the abundances of isotopologues previously measured via balloon and aircraft. These data sets show the usefulness of satellite-based measurements of isotopologues in the upper atmosphere.