Department of Physics
Portland State University
Current Research Areas
Isotopic atmospheric methane
Emissions from rice agriculture
Role of trees in the methane budget
Methyl halide emissions from estuaries
Carbon flux from cities
Method development
Method Development
At low concentrations in the atmosphere, greehouse gases (e.g., methane and nitrous oxide) and other important trace species can be challenging to measure with sufficient precision to characterize spatial and temporal variability in the Earth's system. Additional challenges in senstivity and precision are presented when measuring isotopic composition of atmospheric trace species due to interfering isobars and isotopic fractionation effects in measurement.
Driven by a need to collect data more rapidly than ever, our research group develops and uses novel analytical techniques to measure atmospheric trace species. These include advances in gas chromarography, mass spectrometry and optical cavity enhanced techniques.
Recent published work in method development for cavity ring-down spectroscopy can be found in Review of Scientific Instruments:
Bostrom, G., D. Atkinson, A. Rice, The discrete Fourier transform algorithm for determining decay constants - Implementation using a field programmable gate array, Review of Scientifc Instruments, 86, 043106, 2015
and Optics Letters:
Bostrom, G., A. Rice, D. Atkinson, Optical injection unlocking for cavity ringdown spectroscopy, Optics Letters, 39, 14., 2014
and in a full Ph.D. dissertation by Dr. Gregory Bostrom:
Bostrom, Gregory Alan, Modifications to a Cavity Ringdown Spectrometer to Improve Data Acquisition Rates, Dissertations, Portland State University, Paper 2208, 2015
Information on method development of isotopic atmospheric methane measurements can be found in a dissertation by Dr. Doaa Teama:
Teama, Doaa Galal Mohammed, A 30-Year Record of the Isotopic Composition of Atmospheric Methane, Dissertation, Portland State University, 2013
