Measurement and analysis of rotational lines in the (2ν1+ν2+ν3) overtone band of H2O perturbed by CO2 using near infrared diode laser spectroscopy

Poddar, Palash; Bandyopadhyay, Amitava; Biswas, Debasish; Ray, Biswajit; Ghosh, Pradip N.

doi:10.1016/j.cplett.2008.12.074

Cited by 6 publications

(2 citation statements)

References 23 publications

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“…Very recently Poddar et al [82] measured the CO 2 -induced broadening coefficients in the 2ν 1 +ν 2 +ν 3 overtone band using Voigt profile model and considered the dependence of the broadening coefficients on the rotational quantum numbers.…”

Section: Broadening Of Water Vapour Lines By Nitrogen Oxygen Air Anmentioning

confidence: 99%

Collisional broadening of water vapour lines

Buldyreva¹,

Lavrentieva²,

Starikov³

2010

Collisional Line Broadening and Shifting of Atmospheric Gases

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Despite the fact that the main constituents of the Earth's atmosphere are nitrogen (∼ 79%) and oxygen (∼ 20%), other minor (∼ 1%) pollutants and natural gases (CO 2 , CO, H 2 O, Ar, and so on) play a very important role. A particular place is occupied by water vapour which is the principle absorber of solar radiation concentrated mainly in the spectral region 0.3-15 µm. It is in this region that its strongest vibrotational bands are situated. Currently, about 50,000 spectral transitions of water vapour molecule are identified with the vibrational quantum numbers v 1 + v 2 + v 3 ≤ 10 and the rotational quantum numbers J ≤ 42, K a ≤ 32. _________________________________________________________________ Let us specify the meaning of these quantum numbers. In the Н 2 О molecule, there are three normal vibrational modes, two of which refer to the variations in the OH bond length (stretching vibrations) and one describes the variations of ∠ НОН angle (bending vibration). The symmetric and anti-symmetric stretching vibrations are characterised by the vibrational quantum numbers v 1 and v 3 , whereas the bending vibration is associated with the vibrational quantum number v 2 . Any vibrational state in the molecule is therefore defined by three quantum numbers: V ≡ (v 1 v 2 v 3 ).Since the H 2 O molecule is an asymmetric top, its rotational energy levels [J K a K c ] are defined by three rotational quantum numbers J, K a , K c . The (pseudo-)quantum numbers K a and K c represent the projections of the angular momentum operator along the molecular axes a (axis of the smallest moment of inertia) and c (axis of the largest moment of inertia). They are not good quantum numbers but become them in the limit cases of prolate or oblate symmetric tops, respectively, reducing to the rotational quantum number K. It is for this reason that they are often referred to as pseudoquantum numbers. The point group of symmetry is C 2v , so that all vibrotational states and wave functions belong to one of four symmetry types: A 1 , A 2 , B 1 or B 2 . These types of symmetry (usually denoted by Γ) are presented in Table 3.1 [1]. The symmetry type Γ also defines the nuclear spin statistical weight w needed for the line-broadening and intensity calculations (Table 3.2). The allowed transitions between the vibrotational states of H 2 O molecule are: A 1 ↔ A 2 , B 1 ↔ B 2 , i.e. only the transitions between different A-states (A-bands) or B-states (B-bands) are Collisional Line Broadening and Shifting of Atmospheric Gases Downloaded from www.worldscientific.com by KAINAN UNIVERSITY on 12/27/14. For personal use only. * Here µa and µb are the dipole moment components in the molecular frame with a, b, c axes corresponding to the moments of inertia Ia < Ib < Ic. The molecule lies in the XOZ plane and its symmetry axis OX is the permanent dipole moment axis (i.e. for the equilibrium configuration µx ≠ 0 and µz = 0). Other notations for the rotational states can be found in Refs [1-3]. ___________________________________________________________The knowl...

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Section: Broadening Of Water Vapour Lines By Nitrogen Oxygen Air Anmentioning

confidence: 99%

Collisional broadening of water vapour lines

Buldyreva¹,

Lavrentieva²,

Starikov³

2010

Collisional Line Broadening and Shifting of Atmospheric Gases

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“…The line shape study of water vapour transition perturbed by different buffer gases like Argon, Nitrogen, Oxygen, Carbon dioxide has been done in the recent past by many authors [1][2][3][4].…”

Section: Introductionmentioning

confidence: 99%

Overtone spectroscopy of water molecules based on room temperature diode laser emitting in the NIR range

et al. 2010

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The measurement of very weak overtone spectroscopic line shape of water molecule is performed using wavelength modulation spectroscopy (WMS). In this work a high resolution near infrared diode laser spectrometer is used to record first derivative (1f) signal of buffer gas Helium and Carbon dioxide broadened water vapour transitions around 820 nm wavelength region. The effect of collision due to perturber pressure on signal to noise ratio (SNR) is discussed. The Lorentzian HWHM of observed 1f signal is calculated. The comparison is made between collisional broadening of water vapour transition broadened by inert gas Helium and high quadrupole moment active gas Carbon dioxide.

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Measurements and modeling of absorption by CO2 + H2O mixtures in the spectral region beyond the CO2 ν3-band head

Turbet

Chelin

Landsheere

2018

Icarus

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Measurement and analysis of rotational lines in the (2ν1+ν2+ν3) overtone band of H2O perturbed by CO2 using near infrared diode laser spectroscopy

Cited by 6 publications

References 23 publications

Collisional broadening of water vapour lines

Collisional broadening of water vapour lines

Overtone spectroscopy of water molecules based on room temperature diode laser emitting in the NIR range

Measurements and modeling of absorption by CO2 + H2O mixtures in the spectral region beyond the CO2 ν3-band head

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Measurement and analysis of rotational lines in the (2ν1+ν2+ν3) overtone band of H2O perturbed by CO2 using near infrared diode laser spectroscopy

Cited by 6 publications

References 23 publications

Collisional broadening of water vapour lines

Collisional broadening of water vapour lines

Overtone spectroscopy of water molecules based on room temperature diode laser emitting in the NIR range

Measurements and modeling of absorption by CO2 + H2O mixtures in the spectral region beyond the CO2 ν3-band head

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Measurements and modeling of absorption by CO2 + H2O mixtures in the spectral region beyond the CO2 ν3-band head