المؤلفون: Varanasi, P., Chudamani, S.

الوصف: $^{\dag}$ Supported by the Planetary Atmospheres Branch of the Solar System Exploration Division of NASA under Grant-in-Aid No. NGR 33-015-139 and by the Upper Atmosphere Research Program of the Earth Sciences and Applications Division of NASA under Grant-in-Aid No. NAGW-1238. ; Author Institution: Laboratory for Planetary Atmospheres Research, State University of New York ; Unless very careful and skillful precautions are taken, measurement of collision-induced line shifts using a tunable diode laser can be unreliable on account of the commonly encountered jitter and instability in the laser signal. However, when lines belonging to different molecules appear in the spectral scan as neighbors (reference lines) that do not interfere with the absorption of the observed line, as in the case of the three methanes and N2O, accurate line shift measurement is feasible. Using separate absorption cells for the reference and sample gases and placing them in series, we have been able to measure the pressure-induced shifts of the rotational lines of $^{12}CH_{4}, {^{13}}CH_{4}, {^{12}}CH_{3}D$ and $^{14}N_{2}O$ located between 1265 and $1275 cm^{-1}$. The temperature dependence of the shifts is also presented for collisions of the absorbers with $H_{2}, He, Ar, N_{2}, O$, and air.

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العلاقة: 1988-RF-12; http://hdl.handle.net/1811/17600Test

الإتاحة: http://hdl.handle.net/1811/17600Test

المؤلفون: Varanasi, P., Chudamani, S., Giver, L. P., Valero, Francisco P. J.

الوصف: $^{\ast}$ Supported by NASA Grant-in-Aid NGR 33-015-139 through the Planetary Atmospheres Program to Varanasi. ; Author Institution: Laboratory for Planetary Atmospheres Research, State University of New York; Astrophysical Experiments Branch, NASA Ames Research Center ; Several spectra have been recorded between 150 and 198 K of the $\nu_{3}$-fundamentals of ${^{12}}CH_{4}$ and ${^{12}}C_{2}H_{2}$, and of the $\nu_{1} + \nu_{5}$ band of ${^{12}}C_{2}H_{2}$ with a spectral resolution of $0.06 cm^{-1}$. A comparison is presented between measured line strengths and those listed in published compilations.

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العلاقة: 1984-MF-6; http://hdl.handle.net/1811/16651Test

الإتاحة: http://hdl.handle.net/1811/16651Test

المؤلفون: Chudamani, S.

الوصف: $^{\dag}$ Supported by the Upper Atmosphere Research Program of the Earth Sciences and Applications Division of NASA under Grant-in-Aid No. NAGW-1238. ; Author Institution: Laboratory for Planetary Atmospheres Research, State University of New York ; The need for data on the intensities and air-broadened half-widths of rotational lines in the $\nu_{1}$- fundamental of $^{14}N_{2}O$ and their temperature dependence at temperatures relevant to the terrestrial atmosphere has prompted us to perform measurements on several lines between 1240 and $1280 cm^{-1}$ using a tunable diode laser spectrometer. Line intensities are reported along with $N_{2}$-broadened, $O_{2}$-broadened and air-broadened line width data at several temperatures between 150 and 296 K.

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العلاقة: 1988-TE-5; http://hdl.handle.net/1811/17693Test

الإتاحة: http://hdl.handle.net/1811/17693Test

المؤلفون: Varanasi, P., Chudamani, S.

الوصف: $^{\dag}$ Supported by the Planetary Atmospheres Branch of the Solar System Exploration Division of NASA under Grant-in-Aid No. NCR 33-015-139 and by the Upper Atmosphere Research Program of the Earth Sciences and Applications Division of NASA under Grant-in-Aid No. NAGW-1238. ; Author Institution: Laboratory for Planetary Atmospheres Research, State University of New York ; In the analysis of the observed $^{12}CH_{4}$ spectra of the atmospheres of the major planets, the Saturnian satellite Titan and Earth, intensities and half-width data are required at temperatures between 90 and 288 K on the $\nu_{4}$ lines broadened by $H_{2}, He, N_{2}$ and air. We have, therefore, measured at several temperatures between 100 and 296 K the intensities and half-widths of P(5), P(6), P(9) and P(10) multiplets located between 1240 and $1280 cm^{-1}$ using a tunable diode laser. In addition to the above mentioned broadeners we have also used $O_{2}$ and Ar. The temperature dependence and the relative magnitudes of the line widths of the A, E, F species of rotational lines are examined for each of the broadening cases.

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العلاقة: 1988-RF-11; http://hdl.handle.net/1811/17599Test

الإتاحة: http://hdl.handle.net/1811/17599Test

المؤلفون: Varanasi, P., Chudamani, S.

الوصف: $^{\dag}$ Supported by the Planetary Atmospheres Branch of the Solar System Exploration Division of NASA under Grant-in-Aid No. 33-015-139. ; Author Institution: Laboratory for Planetary Atmospheres Research, State University of New York ; Absolute intensities and $H2$ broadened half-widths of R(0) and R(1) of $^{72}GeH_{4}$ have been measured at 119.5, 150.3, 199.0, 250.0, and 296.0 K using a tunable diode laser and the sweep integration technique. The combined intensity of the $\nu^{3}$ bands of all of the five isotopic species of $GeH_{4}$ as well as that of the Q-branches alone have been measured independently at 294 K using the Wilson-Wells-Penner-Weber technique.

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العلاقة: 1987-FB-10; http://hdl.handle.net/1811/17155Test

الإتاحة: http://hdl.handle.net/1811/17155Test

المؤلفون: Varanasi, P., Chudamani, S., Kapur, S.

الوصف: $^{\ddag}$ Supported by The Atmospheric Sciences Division of NSF under Grant No. ATM 83-17115. ; Author Institution: Laboratory for Planetary Atmospheres Research, State University of New York ; The continuum absorption by water vapor beyond $8 \mu m$ plays an important role in atmospheric remote sensing and climate analysis research studies. The nature of this absorption spectrum and its dependence upon atmospheric temperature, pressure and humidity have been examined in our laboratory. A brief discussion of the existing theoretical models is presented along with new experimental data.

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العلاقة: 1987-FB-12; http://hdl.handle.net/1811/17157Test

الإتاحة: http://hdl.handle.net/1811/17157Test

المؤلفون: Chudamani, S., Varanasi, P., Kapur, S.

الوصف: $^{\dag}$ Supported by the Planetary Atmospheres Branch of the Solar System Exploration Division of NASA under Grant-in-Aid No. 33-015-139. ; Author Institution: Laboratory for Planetary Atmospheres Research, State University of New York ; Analyses of CO spectra observed in the atmospheres of Earth and Titan require $N^{-}_{2}$ broadened line width data at low temperatures. We have, therefore, measured the $N^{-}_{2}$ broadened half-widths of several lines between P(1) and P(15) in the fundamental band of $^{12}C^{16}O$ at 100, 150, 200, 250, and 298 K in our laboratory. Employing a tunable diode laser spectrometer and the sweepintegration technique, the line widths ($cm^{-1} atm^{-1}$) have been found to vary with temperature according to the empirical power law: $\gamma^{\circ} \sim T^{-n}$ with $n = 0.746 \pm 0.016$.

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العلاقة: 1987-FB-11; http://hdl.handle.net/1811/17156Test

الإتاحة: http://hdl.handle.net/1811/17156Test

المؤلفون: Chudamani, S., Varanasi, P.

الوصف: $^{\dag}$ Supported by the Planetary Atmospheres Branch of the Solar System Exploration Division of NASA under Grant-in-Aid No. NGR 33-015-139. ; Author Institution: Laboratory for Planetary Atmospheres Research, State University of New York ; For the determination of the D/H ratio in the atmospheres of of the major planets, the Saturnian satellite Titan and Earth, intensities and half-width data are required at temperatures between 90 and 288 K on the infrared lines of $^{12}CH_{3D}$ broadened by $H_{2}, He, N_{2}$ and air. Using a tunable diode laser and the sweep integration technique, we have measured at several temperatures between 100 and 296 K the intensities and half-widths of several multiplets in the $\nu_{3}$ and $\nu_{6}$ fundamentals of $^{12}CH_{3}D. O_{2}$-broadening and Ar-broadening have also been considered in addition to the broadening by the gases already mentioned.

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العلاقة: 1988-RF-9; http://hdl.handle.net/1811/17610Test

الإتاحة: http://hdl.handle.net/1811/17610Test

المؤلفون: Chudamani, S., Varanasi, P.

الوصف: $^{\dag}$ Supported by the Planetary Atmospheres Branch of the Solar System Exploration Division of NASA under Grant-in-Aid No. 33-015 139 and by the Upper Atmosphere Research Program of the Earth Sciences and Applications Division of NASA under Grant-in-Aid No. NAGW-1238 ; Author Institution: Institute for Atmospheric Sciences, State University of New York ; Accurate knowledge of collision-induced line shifts is required at the relevant atmospheric temperatures in the analysis of the observed $^{12}CH_{4}$ spectra of the atmospheres of the major planets, the Saturnian satellite Titan, and Earth, in addition to intensity and line width data. The appropriate temperatures fall in the range between 90 and 288 K and the relevant perturbers are $H_{2}, He, N_{2}$, and air. Using separate absorption cells for the reference and sample gases and placing them in series, we have been able to measure the pressure-induced shifts of the R(4) and R(7) multiplets located between 1330 and $1350 cm^{-1}$ in the $\nu_{4}$-fundamental of $^{12}CH_{4}$ at several temperatures between 100 and 296 K using a tunable diode laser. The temperature dependence of the shifts is presented for collisions of $^{12}CH_{4}$ with $H_{2}, He, Ar, N_{2}, O_{2}$ and air. The experiments have also yielded data on the intensities and collision-broadened half-widths at the various temperatures. The different variation with temperature of the line width and the line shift for each line measured is discussed.

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العلاقة: 1989-TB-9; http://hdl.handle.net/1811/17941Test

الإتاحة: http://hdl.handle.net/1811/17941Test

المؤلفون: Chudamani, S., Varanasi, P.

الوصف: Supported by the Planetary Atmospheres Branch of the Solar System Exploration Division of NASA under Grant-in-Aid No. 33-015-139. Address of the authors: Laboratory for Planetary Atmospheres Research, State University of New York, Stony Brook, NY 11794-2300 ; Author Institution: ; The spectra of Jupiter and Saturn in the 5 um window contain several lines of CH D. Using a tunable diode laser spectrometer, we have measured hydrogen-broadened and nitrogen-broadened half-widths of several lines in the $\nu_{2}$- fundamental band at 100, 150, 200, 250, and 298 K. The nitrogen braodened line widths are relevant to the study of the $8.6 \mu m$ lines of this molecule found in the spectrum of Titan's atmosphere. The variation of the line parameters with temperature is discussed.

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العلاقة: 1986-TE-11; http://hdl.handle.net/1811/17085Test

الإتاحة: http://hdl.handle.net/1811/17085Test