REVISING THE LINESHAPE PARAMETERS FOR AIR- AND SELF- BROADENED CO2 LINES AT A SUB-PERCENT LEVEL

Characterizing and modelling the atmospheric CO$_2$ with a sub-percent accuracy necessitates high-quality spectroscopic lineshape parameters. For this goal, we collected the best experimentally and theoretically measured lineshape coefficients of CO$_2$ lines broadened by air and CO$_2$ to create sets of semi-empirical models for updating all the transitions of the HITRAN database [1]. Based on the available data, we estimated the air- and CO$_2$- broadening coefficients, their associated temperature exponents, and the speed dependence of the broadening together with its temperature dependence for every transition in HITRAN. Furthermore, the semi-empirical approach proposed by Hartmann 2009 [2] (trained by most reliable experimental data) is used to calculate the line shifts of air- and self- broadened CO$_2$ absorption lines. The updated data will be provided on www.hitran.org and will be used in the next edition of HITRAN. It is notable that thanks to the relational structure of the HITRAN database we provide separate consistent and complete sets of parameters in Voigt and speed-dependent Voigt parametrizations. Finally, the updated lineshape parameters are used for calculating the first-order line mixing using the program developed by Lamouroux et al. [3] which will also be provided in HITRAN 2020. For verifying the semi-empirically calculated lineshape parameters, the laboratory spectra measured by Dr. Keeyoon Sung at the Jet Propulsion Laboratory (JPL) is used to compare with the calculation of the absorption coefficient by HITRAN Application Programming Interface (HAPI) [4] which is now equipped with necessary functionality. [1] JQSRT, 203 (2017) 3-69. [2]JQSRT, 110 (18) (2009) 2019-2026. [3] JQSRT, 151 (2015) 88-96. [4] JQSRT, 177 (2016) 15-30

High resolution spectroscopic study of atmospheric trace gases with climate research application

The presented research was conducted to collect, and analyze the laboratory spectroscopic data together with theoretical calculations of the line shape parameters for the HITRAN (High Resolution Transmission) molecular spectroscopic database. The most updated version of this database is HITRAN2016 \cite{HITRAN16}, and this research has contributed to this database by adding improved laboratory results to it. There is a demand for accurate retrieval of concentration values for carbon dioxide and methane (with accuracy better than 0.3 percent) which requires accurate line shape parameters. These line shape parameters are invaluable for modelling and interpreting spectra of Earth and planetary atmospheres. It is necessary to measure advanced line shape parameters such as the speed-dependence (to explain the impact of the speed of colliding molecules) and line mixing (where there is interference of neighbouring transitions) for all the transitions in the databases. The molecules of interest for the present research are atmospheric trace gases; acetylene (C$_2$H$_2$), methane (CH$_4$) and carbon monoxide (CO). For C$_2$H$_2$, the goal is to determine the fundamental Boltzmann constant based on a line shape analysis of $\nu_1+\nu_3$ band recorded using a tunable diode laser. The next focus of the thesis is the examination of different line profiles on the absorption spectra of the CO-CO$_2$ in the $2-0$ band and CH$_4$-air in 2.3 $\mu m$. A standard multispectrum non-linear least squares fitting technique is used to measure line width and line shift coefficients, and their temperature dependencies considering the effect of speed dependence and line mixing.The Natural Sciences and Engineering Research Council of Canada, the NSERC CREATE AMETHYST, the Alberta Innovates Technology Futures (AITF), the SGS Dean's Scholarship, Department of Physics and Astronomy, and SGS University of Lethbridge

Revising The Lineshape Parameters For Air- And Self- Broadened Co₂ Lines At A Sub-percent Level

Characterizing and modelling the atmospheric CO$_2$ with a sub-percent accuracy necessitates high-quality spectroscopic lineshape parameters. For this goal, we collected the best experimentally and theoretically measured lineshape coefficients of CO$_2$ lines broadened by air and CO$_2$ to create sets of semi-empirical models for updating all the transitions of the HITRAN database [1]. Based on the available data, we estimated the air- and CO$_2$- broadening coefficients, their associated temperature exponents, and the speed dependence of the broadening together with its temperature dependence for every transition in HITRAN. Furthermore, the semi-empirical approach proposed by Hartmann 2009 [2] (trained by most reliable experimental data) is used to calculate the line shifts of air- and self- broadened CO$_2$ absorption lines. The updated data will be provided on www.hitran.org and will be used in the next edition of HITRAN. It is notable that thanks to the relational structure of the HITRAN database we provide separate consistent and complete sets of parameters in Voigt and speed-dependent Voigt parametrizations. Finally, the updated lineshape parameters are used for calculating the first-order line mixing using the program developed by Lamouroux et al. [3] which will also be provided in HITRAN 2020. For verifying the semi-empirically calculated lineshape parameters, the laboratory spectra measured by Dr. Keeyoon Sung at the Jet Propulsion Laboratory (JPL) is used to compare with the calculation of the absorption coefficient by HITRAN Application Programming Interface (HAPI) [4] which is now equipped with necessary functionality. [1] JQSRT, 203 (2017) 3-69. [2]JQSRT, 110 (18) (2009) 2019-2026. [3] JQSRT, 151 (2015) 88-96. [4] JQSRT, 177 (2016) 15-30

“Adopting self-sacrifice”: how Iranian women cope with the sexual problems during the menopausal transition? An exploratory qualitative study

Objective: In the menopausal transition sexual problems are an important issue and one of the most frequently presented health concerns of women attending menopause clinics. This study aimed to explore the ways of managing sexual dysfunctions during the menopausal transition among Iranian women. Methods: This exploratory qualitative study was conducted in Iran, from May 2013 to April 2015. Twenty-one women in three stages of menopausal transition, aged 42–55 years old, were purposively selected from urban health centers in Mashhad and Gonabad, Iran. Semi-structured in depth interviews were conducted for data collection until data saturation was achieved. All interviews were recorded electronically and transcribed verbatim. Conventional content analysis was used for data analysis using Granehiem and Lundman (2004) recommended method. MAXQDA 2007 software was used for organizing data and managing the process of analysis. Results: Data analysis demonstrated one overarching theme entitled “Adopting self-sacrifice” consisting of three categories and seven sub-categories. Major categories included: (1) Confronting decline of libido with two subcategories of women’s libido decline and inability to fulfill husbands’ sexual needs, (2) Seeking strategies for coping with two subcategories of looking for experiences of peer menopausal women and choosing how to interact with the husband and (3) Achieving problem solving strategies with three sub-categories of obedience in sexual relationships (Tamkin), employing affection based on religious advice, and giving up own right to reach mutual understanding. Conclusions: The major finding of this study was “Adopting self-sacrifice” in the process of managing sexual dysfunctions during the menopausal transition. The reason for choosing this passive approach by the majority of women has deep roots in their cultural and traditional beliefs

Analysis of Fourier transform spectra of N2O in the v3 band for atmospheric composition retrievals

We report measurement results for line positions, intensities, half-width, and pressure-induced shift coefficients and line mixing coefficients for N2O broadened by air in the ν3 band. The high signal-to-noise ratio spectra have been recorded at high resolution using the McMath–Pierce Fourier transform spectrometer formerly located at the National Solar Observatory on Kitt Peak, Ariz., USA. The spectra were analyzed using a multispectrum nonlinear least-squares curve-fitting technique employing the speed-dependent Voigt profile with a Rosenkranz (weak) line mixing component. The speed dependence parameters were calculated as suggested in the study of Kochanov (J. Quant. Spectrosc. Radiat. Transf. 189, 18 (2017). doi:10.1016/j.jqsrt.2016.11.007). Several comparisons have been performed between the retrieved parameters and previously published results. For |m| ≤ 40, our results for line positions, broadening, and line mixing coefficients agree best with the results of Loos et al. (J. Quant. Spectrosc. Radiat. Transf. 151, 300 (2015). doi:10.1016/j.jqsrt.2014.10.008). Also, we compared the obtained line positions and intensities with the corresponding values in HITRAN2016 and GEISA-2015 databases. No significant or systematic differences were noticed. The precision of our line positions was estimated to be 3 × 10−5 cm−1. The reported line positions, intensities, and air-broadening coefficients are accurate to better than 2%. The accuracy of air-pressure-induced line shifts and line mixing coefficients is better than 5%. The line mixing coefficients and air-broadening coefficients were also calculated using the exponential power gap scaling law, and these calculated values were found to be in good agreement with the experimental results.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

CO2 pressure broadening and shift coefficients for the 2–0 band of 12C16O

Fourier transform absorption spectra of the 2–0 band of 12C16O mixed with CO2 have been recorded at total pressures from 156 to 1212 hPa and at 4 different temperatures between 240 K and 283 K. CO2 pressure-induced line broadening and line shift coefficients, and the temperature dependence of the former have been measured including line mixing using a multi-spectrum non-linear least squares fitting technique. Different line shape models have been considered to take into account the Dicke narrowing or speed dependence effects. Measured line-shape parameters were compared with theoretical values, calculated for individual temperatures using a semi-empirical method and the Exponential Power Gap (EPG) law.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Revising the line-shape parameters for air- and self-broadened CO2 lines toward a sub-percent accuracy level

International audienc

Recent Line-Shape and Doppler Thermometry Studies Involving Transitions in the ν₁ +ν₃ Band of Acetylene

<p>The line positions for transitions in the <em>ν</em>₁+<em>ν</em>₃band are often used as a frequency standard by the telecom industry and also needed for planetary atmospheric studies. Four relevant studies have been recently carried out in our group and will be discussed briefly below. (1) <em>N</em>₂-broadened line widths and <em>N</em>₂-pressure induced line shifts have been measured for transitions in the <em>ν</em>₁+<em>ν</em>₃band of acetylene at seven temperatures in the range 213333K to obtain the temperature dependences of broadening and shift coefficients. The Voigt and hard-collision line profile models were used to retrieve the line parameters. This study has been published in Molecular Physics, 110 Issue 21/22 (2012) 2645-2663. (2) Six nitrogen perturbed transitions of acetylene within the <em>ν</em>₁+<em>ν</em>₃absorption band have been recorded using a 3-channel diode laser spectrometer. We have examined <em>C</em>₂<em>H</em>₂spectra using a hard collision (Rautian) profile over a range of five temperatures (213 K-333 K). From these fits we have obtained the <em>N</em>₂-broadening and narrowing coefficients of <em>C</em>₂<em>H</em>₂and examined their temperature dependence. The experimentally measured narrowing coefficients have been used to estimate the nitrogen diffusion coefficients. The broadening coefficients and corresponding temperature dependence exponents have also been compared to that of calculations completed using a classical impact approach on an ab initio potential energy surface. We have observed a good agreement between our theoretical and experimental results. This study was published in Canadian Journal of Physics 91(11) 896-905 (2013). (3) An extension of the previous study was to analyze the room temperature for the same six transitions using the Voigt, Rautian, Galatry, RautianGalatry and Correlated Rautian profiles. For the entire pressure range, we have tested the applicability of these line-shape models. Except for Voigt profile, Dicke narrowing effect has been considered in all mentioned line-shape models. The experimental results for the narrowing parameters have been compared with calculated values based on the theory of diffusion. This study is in press in press in the Journal of Quantitative Spectroscopy and Radiative Transfer. (4) In this paper we present accurate measurements of the fundamental Boltzmann constant based on a lineshape analysis of acetylene spectra in the <em>ν</em>₁+<em>ν</em>₃band recorded using a tunable diode laser. Experimental spectra recorded at low pressures have been analyzed using both the Voigt model and the Speed Dependent Voigt model that takes into account the molecular speed dependence effects. These line-shape models reproduces the experimental data with high accuracy and allow us to determine precise line-shape parameters for the transitions used, the Doppler-width and then determined the Boltzmann constant, <em>k</em><em>_B</em>. This study has been submitted for publication in the Journal of Chemical Physics. ¹</p> <p> </p> <p> </p> <p>1 Research described in this work was funded by NSERC, Canada.</p