A table of the equivalent widths of isolated lines with combined Doppler and collision broadened profiles

Jansson, Peter; Korb, C. Laurence

doi:10.1016/0022-4073(68)90115-5

Cited by 149 publications

(16 citation statements)

References 6 publications

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“…Assuming a temperature of 225K and Voigt profiles with a value of a = 0.05, which corresponds to an effective pressure of 6rob, these equivalent widths were converted into total vertical abundances of precipitable water by using water line strengths at 225K given by Farmer (1971) and the tables of Jansson and Korb (1968). Using methods presented by Woodman and Barker (1973) and using the photometric seasonal map of de Vaucouleurs (1967) instead of a uniform disk, airmass values for each observation and slit position were calculated from Martian physical data and estimates oftelluric atmospheric seeing during each observation.…”

Section: Observations Andmentioning

confidence: 99%

Martian atmospheric water vapor observations: 1972–1974 apparition

Barker¹

1976

Icarus

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The patrol of Martian water vapor carried out with the echelle-coudil scanner at McDonald Observatory during the 1972-74 apparition has produced 469 individual photoelectric scans of Doppler-shifted Martian H20 lines. Almost an entire Martian year was covered during the 1972-74 period (L s = 118-269 ° and 301-80°). Three types of coverage have been obtained : ( 1 ) regular--the slit placed pole to pole on the central meridian; (2) latitudinal--the slit placed parallel to the Martian equator at various latitudes; (3) diurnal--the slit placed parallel to the terminator at several times during a Martian day measured from local noon.Both the seasonal and diurnal effects seem to be controlled by the insolation and not the local topography with respect to the 6.1 mb surface. A slight negative correlation with elevation was noted which improved during the seasons of greater H20 content. The previous seasonal behavior has been confirmed and amplified. The following are the primary conclusions: (1) The planetwide abundance is low (5-15~m of ppt H20 ) during both equinoctical periods. (2) The maximum abundance of about 40~am occurs in each hemisphere after solstice at about 40 ° latitude in that hemisphere. (3) The latitude of the maximum amount in the N-S distribution precedes the latitude of maximum insolation by 10-20 ° of latitude. (4) During the "drier" seasons (5-20~m) near the equinoxes on Mars, the atmospheric water vapor changes by a factor of 2-3 × over a diurnal cycle with the maximum near local noon. (5) The effects of the 1973 dust storm during the southern summer reduced the amount of water vapor over the southern hemisphere regions to 3-81zm. INTRODUCTIOI~ AI~D HISTORY

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Section: Observations Andmentioning

confidence: 99%

Martian atmospheric water vapor observations: 1972–1974 apparition

Barker¹

1976

Icarus

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“…High-resolution spectra obtained with balloon-borne and aircraft-borne instruments have provided important simultaneous measurements of stratospheric constituents useful for the study of upper atmospheric chemistry Ecf. Goldman et al, 1980;Buijs et al, 1980;Farmer et al, 1980;Coffey et al, 1981;Louisnard et al, 1983•. Such spectra also contain important information on the isotopic composition of the observed gases that can provide additional insight into their origin.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous stratospheric measurements of H₂O, HDO, and CH₄ from balloon‐borne and aircraft infrared solar absorption spectra and tunable diode laser laboratory spectra of HDO

Rinsland¹,

Goldman²,

Devi³

et al. 1984

J. Geophys. Res.

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High‐resolution infrared solar absorption spectra recorded from a balloon‐borne platform at 33‐km altitude and an aircraft at 12‐km altitude have been analyzed to derive simultaneous stratospheric concentrations of H2O, HDO, and CH4. The data were obtained near 33°N with the University of Denver interferometer during a balloon flight in October 1979 and with the NCAR interferometer aboard a Sabreliner aircraft in September 1982. The analysis of the balloon spectra indicates the H2O mixing ratio increased from 3.5 to 4.8 ppmv and the CH4 mixing ratio decreased from 1.15 to 0.70 ppmv between 18 to 38 km. Tunable diode laser laboratory spectra were recorded and analyzed to derive absolute intensities and air‐broadened half widths of selected lines of the v2 band of HDO. With these parameters, which are reported here, an HDO profile that increases from 0.61 ppbv near 18 km to 0.88 ppbv near 29 km is inferred from the balloon spectra, corresponding to a D/H ratio, normalized to the reference value of 158 atomic parts per million of Standard Mean Ocean Water (SMOW), of 0.55 to 0.67. The average D/H value of 0.40 above 12 km, derived from the aircraft spectra, provides additional spectroscopic evidence for a large depletion in the D content of water vapor in the lower stratosphere. The simultaneous vertical profiles for the three gases retrieved from the balloon spectra are consistent, within the estimated precision of the data (±10%), with methane oxidation as the sole source of stratospheric H2O in addition to H2O transported upward through the tropopause. However, there is an indication of a small increase in the total hydrogen in H2O and CH4 with altitude, and we believe more precise simultaneous measurements are required.

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“…The observed line strengths were deduced from the equivalent width using the Jansson and Korb method [9] adapted for direct computation by Dang-Nhu and Ogilvie [lo]. In principle, the EWM has the great advantage of being independent of the instrumental distortion.…”

Section: Equivalent Width Methodsmentioning

confidence: 99%

Absolute intensity measurements in the ν₃band of carbon disulphide

et al. 2003

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The aim of this paper is to determine with accuracy the band strength of the strong u3 fundamental band of carbon disul hide CS2. By diode-laser spectroscopy, we have measured line by line the intensities for the I C32S2 form by the equivalent width method and by the line profile fitting method. To confirm our results, we have also measured 30 lines for the 13C32S2 isotopic species using a sample of CS2 in natural abundance. We have obtained for the band strength St = 1417cmp2 atm-I at 296K and this value is in good agreement with the values from the literature. P IntroductionThe intensity of spectral lines provides important information for gas analysis and leads to essential results for molecules of atmospheric and astrophysical interest. In particular, the measurements of lines belonging to the more intense transitions are usually needed for these applications. However, for the very intense bands, accurate measurements of the band strength are more difficult to obtain. To record lines of these bands, the product PL of the gas pressure P and the absorption length L has to be small and thus it is difficult to achieve good relative precision.With a view to obtaining as good results as possible, we employed three different methods of absolute line intensity determination. First, we used the classical method of measuring the equivalent width of the line at low pressure (of the order of 0.1 mbar) and at very low path length to maintain the product PL at convenient values. The second method is based on the determination of the line strength by fitting a theoretical profile on the line broadened by an inactive gas such as nitrogen. In this case, the active gas pressure and the path length may become larger, and the line strength is extracted from nonlinear least squares fitting of the spectra with Voigt and Rautian profiles. Finally, as the isotopic substitution modifies the band strength value only slightly, a confirmation can be obtained by measuring the intensity of the lines for the same transition of the less abundant isotopic species.

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A table of the equivalent widths of isolated lines with combined Doppler and collision broadened profiles

Cited by 149 publications

References 6 publications

Martian atmospheric water vapor observations: 1972–1974 apparition

Martian atmospheric water vapor observations: 1972–1974 apparition

Simultaneous stratospheric measurements of H₂O, HDO, and CH₄ from balloon‐borne and aircraft infrared solar absorption spectra and tunable diode laser laboratory spectra of HDO

Absolute intensity measurements in the ν₃band of carbon disulphide

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A table of the equivalent widths of isolated lines with combined Doppler and collision broadened profiles

Cited by 149 publications

References 6 publications

Martian atmospheric water vapor observations: 1972–1974 apparition

Martian atmospheric water vapor observations: 1972–1974 apparition

Simultaneous stratospheric measurements of H2O, HDO, and CH4 from balloon‐borne and aircraft infrared solar absorption spectra and tunable diode laser laboratory spectra of HDO

Absolute intensity measurements in the ν3band of carbon disulphide

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Product

Resources

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Simultaneous stratospheric measurements of H₂O, HDO, and CH₄ from balloon‐borne and aircraft infrared solar absorption spectra and tunable diode laser laboratory spectra of HDO

Absolute intensity measurements in the ν₃band of carbon disulphide