Files in this item
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application/vnd.openxmlformats-officedocument.presentationml.presentation ![]() | Presentation | Microsoft PowerPoint 2007 |
application/pdf ![]() | Abstract |
Description
Title: | High resolution photoacoustic spectroscopy of the oxygen a-band |
Author(s): | Cich, Matthew J. |
Contributor(s): | Okumura, Mitchio; Hodges, Joseph T.; Long, David A.; Miller, Charles; Drouin, Brian; Crawford, Timothy J.; Rupasinghe, Priyanka; Hogan, Daniel; Bray, Caitlin; Bui, Thinh Quoc; Stroscio, Gautam; Lunny, Elizabeth M. |
Subject(s): | Spectroscopy in Atmospheric Chemistry |
Abstract: | NASA’s Orbiting Carbon Observatory missions require spectroscopic parameterization of the Oxygen A-Band absorption (757-775 nm) with unprecedented detail to meet the objective of delivering space-based column CO2 measurements with an accuracy of better than 1 ppm, and spectroscopic parameters with accuracies at the 0.1\% level. To achieve this it is necessary for line shape models to include deviations from the Voigt line shape, including the collisional effects of speed-dependence, line mixing (LM), and collision-induced absorption (CIA). LM and CIA have been difficult to quantify in FTIR and CRDS spectra which have been limited to lower pressure measurements. A photoacoustic spectrometer has been designed to study the pressure- dependence of the spectral line shape up to pressures of 5 atm, where LM and CIA contribute significantly to the A-Band absorption. This spectrometer has a high signal-to-noise (S/N) of about 10,000 and frequency accuracy of 2 MHz. In addition, temperature-dependent effects on the line shape are studied using PID-controlled cooled nitrogen flow/ heater system. The latest acquired spectra and analysis are reported here. |
Issue Date: | 2016-06-22 |
Publisher: | International Symposium on Molecular Spectroscopy |
Genre: | Conference Paper / Presentation |
Type: | Text |
Language: | En |
URI: | http://hdl.handle.net/2142/91151 |
Rights Information: | Copyright 2016 by the authors |
Date Available in IDEALS: | 2017-01-26 |