University of Illinois Urbana-Champaign

ARGON PRESSURE BROADENING IN THE OXYGEN A-BAND

Stevenson, Leah E.

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7193.pdf
TE07_1.pptx

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https://hdl.handle.net/2142/122664

Description

Title
ARGON PRESSURE BROADENING IN THE OXYGEN A-BAND
Author(s)
Stevenson, Leah E.
Contributor(s)
  • Hodges, Joseph T.
  • Okumura, Mitchio
  • Adkins, Erin M.
Issue Date
2023-06-20
Keyword(s)
Small molecules
Abstract
The oxygen A-band, centered at 760 nm, is commonly used in space- and ground-based remote sensing to determine air mass because of the constant mixing ratio of oxygen in Earth’s atmosphere. Since the retrieved air mass has a direct impact on measured concentrations of target species like carbon dioxide, increasingly precise greenhouse gas measurements require high-accuracy spectroscopy of the A-band. Pressure broadening, which results from collisions between the absorbing species and other atoms or molecules, dominates line widths in the A-band and is dependent on the identity of the collision partner. Pressure broadening by argon, which comprises 0.934% of Earth’s atmosphere by volume, is typically neglected in atmospheric and laboratory measurements of the A-band. To investigate the magnitude of pressure broadening by argon, we used cavity ring-down spectroscopy to measure lineshapes of high J" lines in the P-branch of the oxygen A-band over a range of pressures and argon concentrations. Argon foreign-broadening parameters for these lines were determined in combination with other lineshape parameters using a multi-spectrum fitting algorithm. In addition to comparing the results to literature values, we will discuss the implications of including argon pressure broadening in atmospheric and laboratory measurements of the A-band.
Publisher
International Symposium on Molecular Spectroscopy
Type of Resource
Text
Genre of Resource
Conference Paper / Presentation
Language
eng
Handle URL
https://hdl.handle.net/2142/122664
DOI
https://doi.org/10.15278/isms.2023.7193

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Abstracts & Presentations - 2023 International Symposium on Molecular Spectroscopy PRIMARY