Experimental and simulated study of line-shape models for measuring spectroscopic parameters using the WM-DAS method Part II: Broadening and narrowing of select near-infrared H2O and CO lines perturbed by Ar, N2 and He

2021 ◽  
pp. 107790
Author(s):  
Jidong Li ◽  
Yanjun Du ◽  
Yanjun Ding ◽  
Zhimin Peng
Keyword(s):  
Line Shape ◽  
Near Infrared ◽  
Spectroscopic Parameters ◽  
Shape Models

scholarly journals Using a speed-dependent Voigt line shape to retrieve O<sub>2</sub> from Total Carbon Column Observing Network solar spectra to improve measurements of XCO<sub>2</sub>

2019 ◽  
Vol 12 (1) ◽  
pp. 35-50 ◽  
Author(s):  
Joseph Mendonca ◽  
Kimberly Strong ◽  
Debra Wunch ◽  
Geoffrey C. Toon ◽  
David A. Long ◽  
...  
Keyword(s):  
Line Shape ◽  
Near Infrared ◽  
Total Carbon ◽  
Absorption Coefficients ◽  
Line Shapes ◽  
Shape Models ◽  
Speed Dependence ◽  
Measured Absorption ◽  
The Difference ◽  
Carbon Dioxide Co2

Abstract. High-resolution, laboratory, absorption spectra of the a1Δg←X3Σg- oxygen (O2) band measured using cavity ring-down spectroscopy were fitted using the Voigt and speed-dependent Voigt line shapes. We found that the speed-dependent Voigt line shape was better able to model the measured absorption coefficients than the Voigt line shape. We used these line shape models to calculate absorption coefficients to retrieve atmospheric total columns abundances of O2 from ground-based spectra from four Fourier transform spectrometers that are a part of the Total Carbon Column Observing Network (TCCON). Lower O2 total columns were retrieved with the speed-dependent Voigt line shape, and the difference between the total columns retrieved using the Voigt and speed-dependent Voigt line shapes increased as a function of solar zenith angle. Previous work has shown that carbon dioxide (CO2) total columns are better retrieved using a speed-dependent Voigt line shape with line mixing. The column-averaged dry-air mole fraction of CO2 (XCO2) was calculated using the ratio between the columns of CO2 and O2 retrieved (from the same spectra) with both line shapes from measurements taken over a 1-year period at the four sites. The inclusion of speed dependence in the O2 retrievals significantly reduces the air mass dependence of XCO2, and the bias between the TCCON measurements and calibrated integrated aircraft profile measurements was reduced from 1 % to 0.4 %. These results suggest that speed dependence should be included in the forward model when fitting near-infrared CO2 and O2 spectra to improve the accuracy of XCO2 measurements.

First line shape analysis and spectroscopic parameters for the ν11 band of 12C2H4

2016 ◽  
Vol 184 ◽  
pp. 297-307 ◽  
Author(s):  
Et-touhami Es-sebbar ◽  
John Mantzaras ◽  
Yves Benilan ◽  
Aamir Farooq
Keyword(s):  
Shape Analysis ◽  
Line Shape ◽  
First Line ◽  
Spectroscopic Parameters ◽  
Line Shape Analysis

scholarly journals Laboratory spectral calibration of the TanSat atmospheric carbon dioxide grating spectrometer

2018 ◽  
Vol 7 (3) ◽  
pp. 245-252 ◽  
Author(s):  
Zhongdong Yang ◽  
Yuquan Zhen ◽  
Zenshan Yin ◽  
Chao Lin ◽  
Yanmeng Bi ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Spectral Resolution ◽  
Line Shape ◽  
Atmospheric Carbon Dioxide ◽  
Near Infrared ◽  
Shape Function ◽  
Grating Spectrometer ◽  
Spectral Calibration ◽  
Atmospheric Carbon ◽  
Line Shape Function

Abstract. TanSat is a key satellite mission in the Chinese Earth Observation program and is designed to measure the global atmospheric column-averaged dry-air CO2 mole fraction by measuring the visible and near-infrared solar-reflected spectra. The first Chinese super-high-resolution grating spectrometer for measuring atmospheric CO2 is aboard TanSat. This spectrometer is a suite incorporating three grating spectrometers that make coincident measurements of reflected sunlight in the near-infrared CO2 band near 1.61 and 2.06 µm and in the molecular oxygen (O2) A-band at 0.76 µm. The spectral resolving power (λ∕Δλ) values are ∼19 000, ∼12 800, and ∼12 250 in the O2 A-band, and the weak and strong absorption bands of CO2, respectively. This paper describes the prelaunch spectral calibration of the atmospheric carbon dioxide grating spectrometer aboard TanSat. Several critical aspects of the spectrometer, including the spectral resolution, spectral dispersion, and the instrument line shape function of each channel, which are directly related to producing the Level 1 products are evaluated in this paper. The instrument line shape function of the spectrometer is notably symmetrical and perfectly consistent across all channels in the three bands. The symmetry is better then 99.99 %, and the consistency in the worst case is better then 99.97 %, 99.98 %, and 99.98 % in the O2 A, WCO2, and SCO2 bands, respectively. The resulting variations in the spectral calibrations and the radiometric response errors are negligible. The spectral resolution characterizations meet the mission requirements. The spectral dispersions have excellent consistency in the spatial dimension of each band, and there is good linearity in the spectral dimension of each band. The RMS errors of the fitting residuals are 0.9, 1, and 0.7 pm in the O2 A-band, the WCO2 band, and the SCO2 band, respectively. Taken together, these results suggest that the spectral characterizations of the spectrometer aboard TanSat meet the mission requirements.

scholarly journals The air-broadened, near-infrared CO2 line shape in the spectrally isolated regime: Evidence of simultaneous Dicke narrowing and speed dependence

2011 ◽  
Vol 135 (6) ◽  
pp. 064308 ◽  
Author(s):  
David A. Long ◽  
Katarzyna Bielska ◽  
Daniel Lisak ◽  
Daniel K. Havey ◽  
Mitchio Okumura ◽  
...  
Keyword(s):  
Line Shape ◽  
Near Infrared ◽  
Speed Dependence

Line-shape models testing on six acetylene transitions in the ν1+ν3 band broadened by N2

2014 ◽  
Vol 140 ◽  
pp. 58-66 ◽  
Author(s):  
Robab Hashemi ◽  
Hoimonti Rozario ◽  
Chad Povey ◽  
Adriana Predoi-Cross
Keyword(s):  
Line Shape ◽  
Shape Models

Semi-classical line shape models of rovibrational H[sub 2]O spectra tested using frequency-stabilized cavity ring-down spectroscopy

2008 ◽  
Author(s):  
R. Ciuryło ◽  
D. Lisak ◽  
J. T. Hodges ◽  
Marco Antonio Gigosos ◽  
Manuel Ángel González
Keyword(s):  
Line Shape ◽  
Cavity Ring Down Spectroscopy ◽  
Shape Models ◽  
Cavity Ring Down
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