References of "Goldman, A"
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See detailObserved and simulated time evolution of HCl, ClONO2, and HF total column abundances
Kohlhepp, R; Ruhnke, R; Chipperfield, M P et al

in Atmospheric Chemistry and Physics (2012), 12(7), 3527--3556

Time series of total column abundances of hydrogen chloride (HCl), chlorine nitrate (ClONO2), and hydrogen fluoride (HF) were determined from ground-based Fourier transform infrared (FTIR) spectra ... [more ▼]

Time series of total column abundances of hydrogen chloride (HCl), chlorine nitrate (ClONO2), and hydrogen fluoride (HF) were determined from ground-based Fourier transform infrared (FTIR) spectra recorded at 17 sites belonging to the Network for the Detection of Atmospheric Composition Change (NDACC) and located between 80.05°N and 77.82°S. By providing such a near-global overview on ground-based measurements of the two major stratospheric chlorine reservoir species, HCl and ClONO2, the present study is able to confirm the decrease of the atmospheric inorganic chlorine abundance during the last few years. This decrease is expected following the 1987 Montreal Protocol and its amendments and adjustments, where restrictions and a subsequent phase-out of the prominent anthropogenic chlorine source gases (solvents, chlorofluorocarbons) were agreed upon to enable a stabilisation and recovery of the stratospheric ozone layer. The atmospheric fluorine content is expected to be influenced by the Montreal Protocol, too, because most of the banned anthropogenic gases also represent important fluorine sources. But many of the substitutes to the banned gases also contain fluorine so that the HF total column abundance is expected to have continued to increase during the last few years. The measurements are compared with calculations from five different models: the two-dimensional Bremen model, the two chemistry-transport models KASIMA and SLIMCAT, and the two chemistry-climate models EMAC and SOCOL. Thereby, the ability of the models to reproduce the absolute total column amounts, the seasonal cycles, and the temporal evolution found in the FTIR measurements is investigated and inter-compared. This is especially interesting because the models have different architectures. The overall agreement between the measurements and models for the total column abundances and the seasonal cycles is good. Linear trends of HCl, ClONO2, and HF are calculated from both measurement and model time series data, with a focus on the time range 2000–2009. This period is chosen because from most of the measurement sites taking part in this study, data are available during these years. The precision of the trends is estimated with the bootstrap resampling method. The sensitivity of the trend results with respect to the fitting function, the time of year chosen and time series length is investigated, as well as a bias due to the irregular sampling of the measurements. The measurements and model results investigated here agree qualitatively on a decrease of the chlorine species by around 1%yr-1. The models simulate an increase of HF of around 1%yr-1. This also agrees well with most of the measurements, but some of the FTIR series in the Northern Hemisphere show a stabilisation or even a decrease in the last few years. In general, for all three gases, the measured trends vary more strongly with latitude and hemisphere than the modelled trends. Relative to the FTIR measurements, the models tend to underestimate the decreasing chlorine trends and to overestimate the fluorine increase in the Northern Hemisphere. At most sites, the models simulate a stronger decrease of ClONO2 than of HCl. In the FTIR measurements, this difference between the trends of HCl and ClONO2 depends strongly on latitude, especially in the Northern Hemisphere. [less ▲]

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See detailAn empirical line-by-line model for the infrared solar transmittance spectrum from 700 to 5000 cm(-1)
Hase, F.; Demoulin, Philippe ULg; Sauval, A. J. et al

in Journal of Quantitative Spectroscopy & Radiative Transfer (2006), 102(3), 450-463

An empirical line-by-line model for the infrared solar transmittance spectrum is presented. The model can be incorporated into radiative transfer codes to allow fast calculation of all relevant emission ... [more ▼]

An empirical line-by-line model for the infrared solar transmittance spectrum is presented. The model can be incorporated into radiative transfer codes to allow fast calculation of all relevant emission and absorption features in the solar spectrum in the mid-infrared region from 700 to 5000 cm(-1). The transmittance is modelled as a function of the diameter of the field-of-view centered on the solar disk: the line broadening due to solar rotation as well as center-to-limb variations in strength and width are taken into account for stronger lines. Applications of the model presented here are in the fields of terrestrial remote sensing in the mid-infrared spectral region when the sun is used as radiation source or scattered solar radiation contributes to the measured signal and in the fields of atmospheric radiative transfer algorithms which compute the propagation of infrared solar radiation in the terrestrial atmosphere. (c) 2006 Elsevier Ltd. All rights reserved. [less ▲]

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See detailCorrelation relationships of stratospheric molecular constituents from high spectral resolution, ground-based infrared solar absorption spectra
Rinsland, C. P.; Goldman, A.; Connor, B. J. et al

in Journal of Geophysical Research. Atmospheres (2000), 105(D11), 14637-14652

Comparisons of chemically active species with chemically inert tracers are useful to quantify transport and mixing and assess the accuracy of model predictions. We report measurements of chemically active ... [more ▼]

Comparisons of chemically active species with chemically inert tracers are useful to quantify transport and mixing and assess the accuracy of model predictions. We report measurements of chemically active species and chemically inert tracers in the stratosphere derived from the analysis of infrared solar absorption spectra recorded with a ground-based Fourier transform spectrometer operated typically at 0.005- to 0.01-cm(-1) spectral resolution. The measurements were recorded from Kitt Peak in southern Arizona (latitude 31.9 degrees N, 111.6 degrees W, 2.09 km altitude). Time series of N2O, CH4, O3, and HNO3 vertical profiles have been retrieved from measurements in microwindows. From these results, correlations between N2O and CH4 stratospheric mixing ratios and between O3 and HNO3 lower stratospheric mixing ratios have been derived. The measured correlations between N2O versus CH4 mixing ratios are compact and show little variability with respect to season in quantitative agreement with Atmospheric Trace Molecule Spectroscopy Experiment (ATMOS) spring and autumn measurements recorded near the same latitude. Lower stratospheric O3 versus HNO3 mixing ratios measured during low to moderate aerosol loading time periods also show a compact relations though the HNO3/O3 slope is a factor of 2 lower than obtained from November 1994 ATMOS measurements near the Same latitude. We also compare Kitt Peak and ATMOS N2O versus CH4 and O3 versus HNO3 relations obtained by averaging the measurements over two broad stratospheric layers. This comparison avoids bias from the a priori profiles and the limited vertical resolution of the ground-based observations. [less ▲]

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See detailPolar stratospheric descent of NOy and CO and Arctic denitrification during winter 1992-1993
Rinsland, C. P.; Salawitch, R. J.; Gunson, M. R. et al

in Journal Of Geophysical Research. Atmospheres (1999), 104(D1), 1847-1861

Observations inside the November 1994 Antarctic stratospheric vortex and inside the April 1993 remnant Arctic stratospheric vortex by the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier transform ... [more ▼]

Observations inside the November 1994 Antarctic stratospheric vortex and inside the April 1993 remnant Arctic stratospheric vortex by the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier transform spectrometer are reported. In both instances, elevated volume mixing ratios (VMRs) of carbon monoxide (CO) were measured. A peak Antarctic CO VMR of 60 ppbv (where 1 ppbv = 10(-9) per unit volume) was measured at a potential temperature (Theta) of 710 K (similar to 27 km), about 1 km below the altitude of a pocket of elevated NOy (total reactive nitrogen) at a deep minimum in N2O (<5 ppbv). The Arctic observations also show a region of elevated vortex CO with a peak VMR of 90 ppbv at 630-670 K (similar to 25 km) but no corresponding enhancement in NOy, perhaps because of stronger dynamical activity in the northern hemisphere polar winter and/or interannual variability in the production of mesospheric NO. By comparing vortex and extravortex observations of NOy obtained at the same N2O VMR, Arctic vortex denitrification of 5 +/- 2 ppbv at 470 K (similar to 18 km) is inferred. We show that our conclusion of substantial Arctic winter 1992-1993 denitrification is robust by comparing our extravortex observations with previous polar measurements obtained over a wide range of winter conditions. Correlations of NOy with N2O measured at the same Theta by ATMOS in the Arctic vortex and at midlatitudes on board the ER-2 aircraft several weeks later lie along the same mixing line. The result demonstrates the consistency of the two data sets and confirms that the ER-2 sampled fragments of the denitrified Arctic vortex following its breakup, An analysis of the ATMOS Arctic measurements of total hydrogen shows no evidence for significant dehydration inside the vortex. [less ▲]

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See detailATMOS/ATLAS 3 infrared profile measurements of clouds in the tropical and subtropical upper troposphere
Rinsland, C. P.; Gunson, M. R.; Wang, P.-H. et al

in Journal of Quantitative Spectroscopy & Radiative Transfer (1998), 60(5), 903-919

Vertical profiles of infrared cirrus extinction have been derived from tropical and subtropical upper tropospheric solar occultation spectra. The measurements were recorded by the Atmospheric Trace ... [more ▼]

Vertical profiles of infrared cirrus extinction have been derived from tropical and subtropical upper tropospheric solar occultation spectra. The measurements were recorded by the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier transform spectrometer during the Atmospheric Laboratory for Applications and Sciences (ATLAS) 3 shuttle flight in November 1994. The presence of large numbers of small ice crystals is inferred from the appearance of broad extinction features in the 8-12 mu m region. These features were observed near the tropopause and at lower altitudes. Vertical profiles of the ice extinction (km(-1)) in microwindows at 831, 957, and 1204 cm(-1) have been retrieved from the spectra and analyzed with a model for randomly oriented spheroidal ice crystals. An area-equivalent spherical radius of 6 mu m is estimated from the smallest ice crystals observed in the 8-12 mu m region. Direct penetration of clouds into the lower stratosphere is inferred from observations of cloud extinction extending from the upper troposphere to 50 mbar (20 km altitude). Cloud extinction between 3 and 5 mu m shows very little wavelength dependence, at least for the cases observed by the ATMOS instrument in the tropics and subtropics during ATLAS 3. Published by Elsevier Science Ltd. [less ▲]

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See detailATMOS/ATLAS 3 infrared profile measurements of trace gases in the November 1994 tropical and subtropical upper troposphere
Rinsland, C. P.; Gunson, M. R.; Wang, P.-H. et al

in Journal of Quantitative Spectroscopy & Radiative Transfer (1998), 60(5), 891-901

Vertical mixing ratio profiles of four relatively long-lives gases, HCN, C2H2, CO, and C2H6, have been retrieved from 0.01 cm(-1) resolution infrared solar occultation spectra recorded between latitudes ... [more ▼]

Vertical mixing ratio profiles of four relatively long-lives gases, HCN, C2H2, CO, and C2H6, have been retrieved from 0.01 cm(-1) resolution infrared solar occultation spectra recorded between latitudes of 5.3 degrees N and 31.4 degrees N. The observations were obtained by the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier transform spectrometer during the Atmospheric Laboratory for Applications and Science (ATLAS) 3 shuttle flight, 3-12 November 1994. Elevated mixing ratios below the tropopause were measured for these gases during several of the occultations. The positive correlations obtained between the simultaneously measured mixing ratios suggest that the enhancements are likely the result of surface emissions, most likely biomass burning and/or urban industrial activities, followed by common injection via deep convective transport of the gases to the upper troposphere. The elevated levels of HCN may account for at least part of the "missing NOy" in the upper troposphere. Comparisons of the observations with values measured during a recent aircraft campaign are presented. Published by Elsevier Science Ltd. [less ▲]

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See detailNorthern and southern hemisphere ground-based infrared spectroscopic measurements of tropospheric carbon monoxide and ethane
Rinsland, C. P.; Jones, N. B.; Connor, B. J. et al

in Journal Of Geophysical Research. Atmospheres (1998), 103(D21), 28197-28217

Time series of CO and C2H6 measurements have been derived from high-resolution infrared solar spectra recorded in Lauder, New Zealand (45.0 degrees S, 169.7 degrees E, altitude 0.37 km), and at the U.S ... [more ▼]

Time series of CO and C2H6 measurements have been derived from high-resolution infrared solar spectra recorded in Lauder, New Zealand (45.0 degrees S, 169.7 degrees E, altitude 0.37 km), and at the U.S. National Solar Observatory (31.9 degrees N, 111.6 degrees W, altitude 2.09 km) on Kitt Peak. Lauder observations were obtained between July 1993 and November 1997, while the Kitt Peak measurements were recorded between May 1977 and December 1997. Both databases were analyzed with spectroscopic parameters that included significant improvements for C2H6 relative to previous studies. Target CO and C2H6 lines were selected to achieve similar vertical samplings based on averaging kernels. These calculations show that partial columns from layers extending from the surface to the mean tropopause and from the mean tropopause to 100 km are nearly independent. Retrievals based on a semiempirical application of the Rodgers optimal estimation technique are reported for the lower laver, which has a broad maximum in sensitivity in the upper troposphere. The Lauder CO and C2H6 partial columns exhibit highly asymmetrical seasonal cycles with minima in austral autumn and sharp peaks in austral spring. The spring maxima are the result of tropical biomass burning emissions followed by deep convective vertical transport to the upper troposphere and long-range horizontal transport. Significant year-to-year variations are observed for both CO and C2H6, but the measured trends, (+0.37 +/- 0.57)% yr(-1) and (-0.64 +/- 0.79)% yr(-1), 1 sigma, respectively, indicate no significant long-term changes. The Kitt Peak data also exhibit CO and C2H6 seasonal variations in the lower layer with trends equal to (-0.27 +/- 0.17)% yr(-1) and (-1.20 +/- 0.35')% yr(-1), 1 sigma, respectively. Hence a decrease in the Kitt Peak tropospheric C2H6 column has been detected, though the CO trend is not significant. Both measurement sets are compared with previous observations, reported trends, and three-dimensional model calculations. [less ▲]

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See detailThe 1994 northern midlatitude budget of stratospheric chlorine derived from ATMOS/ATLAS-3 observations
Zander, Rodolphe ULg; Mahieu, Emmanuel ULg; Gunson, M. R. et al

in Geophysical Research Letters (1996), 23(17), 2357-2360

Volume mixing ratio (VMR) profiles of the chlorine-bearing gases HCl, ClONO2, CCl3F, CCl2F2, CHClF2, CCl4, and CH3Cl have been measured between 3 and 49 degrees northern- and 65 to 72 degrees southern ... [more ▼]

Volume mixing ratio (VMR) profiles of the chlorine-bearing gases HCl, ClONO2, CCl3F, CCl2F2, CHClF2, CCl4, and CH3Cl have been measured between 3 and 49 degrees northern- and 65 to 72 degrees southern latitudes with the Atmospheric Trace MOlecule Spectroscopy (ATMOS) instrument during the ATmospheric Laboratory for Applications and Science (ATLAS)-3 shuttle mission of 3 to 12 November 1994. A subset of these profiles obtained between 20 and 49 degrees N at sunset, combined with ClO profiles measured by the Millimeter-wave Atmospheric Sounder (MAS) also from aboard ATLAS-3, measurements by balloon for HOCl, CH3CCl3 and C2Cl3F3, and model calculations for COClF indicates that the mean burden of chlorine, Cl-TOT, was equal to (3.53 +/- 0.10) ppbv (parts per billion by volume), 1-sigma, throughout the stratosphere at the time of the ATLAS 3 mission. This is some 37% larger than the mean 2.58 ppbv value measured by ATMOS within the same latitude zone during the Spacelab 3 flight of 29 April to 6 May 1985, consitent with an exponential growth rate of the chlorine loading in the stratosphere equal to 3.3%/yr or a linear increase of 0.10 ppbv/yr over the Spring-1985 to Fall-1994 time period. These findings are in agreement with both the burden and increase of the main anthropogenic Cl-bearing source gases at the surface during the 1980s, confirming that the stratospheric chlorine loading is primarily of anthropogenic origin. [less ▲]

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See detailATMOS/ATLAS-3 measurements of stratospheric chlorine and reactive nitrogen partitioning inside and outside the November 1994 Antarctic vortex
Rinsland, Curtis P.; Gunson, Michael R.; Salawitch, R. J. et al

in Geophysical Research Letters (1996), 23(17), 2365-2368

Partitioning between HCl and ClONO2 and among the main components of the reactive nitrogen family (NO, NO2, HNO3, ClONO2, N2O5, and HO2NO2) has been studied inside and outside the Antarctic stratospheric ... [more ▼]

Partitioning between HCl and ClONO2 and among the main components of the reactive nitrogen family (NO, NO2, HNO3, ClONO2, N2O5, and HO2NO2) has been studied inside and outside the Antarctic stratospheric vortex based on ATMOS profiles measured at sunrise during the 3-12 November 1994 ATLAS-3 Shuttle mission. Elevated mixing ratios of HCl in the lower stratosphere with a peak of similar to 2.9 ppbv (10(-9) parts per volume) were measured inside the vortex near 500 K potential temperature (similar to 19 km). Maximum ClONO2 mixing ratios of similar to 1.2, similar to 1.4, and similar to 0.9 ppbv near 700 K (similar to 25 km) were measured inside, at the edge, and outside the vortex, respectively. Model calculations reproduce the higher levels of HCl and NOx (NO + NO2) inside the lower stratospheric vortex both driven by photochemical processes initiated by low O3. The high HCl at low O3 results from chemical production of HCl via the reaction of enhanced Cl with CH4, limited production of ClONO2, and the descent of inorganic chlorine from higher altitudes. [less ▲]

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See detailIncrease of stratospheric carbon tetrafluoride (CF4) based on ATMOS observations from space
Zander, Rodolphe ULg; Solomon, S.; Mahieu, Emmanuel ULg et al

in Geophysical Research Letters (1996), 23(17), 2353-2356

Stratospheric volume mixing ratio profiles of carbon tetrafluoride, CF4, obtained with the Atmospheric Trace Molecule Spectroscopy (ATMOS) instrument during the ATLAS (Atmospheric Laboratory for ... [more ▼]

Stratospheric volume mixing ratio profiles of carbon tetrafluoride, CF4, obtained with the Atmospheric Trace Molecule Spectroscopy (ATMOS) instrument during the ATLAS (Atmospheric Laboratory for Applications and Science) -3 mission of 1994 are reported. Overall the profiles are nearly constant over the altitude range 20 to 50 km, indicative of the very long lifetime of CF4 in the atmosphere. In comparison to the stratospheric values of CF4 inferred from the ATMOS/Spacelab 3 mission of 1985, the 1994 concentrations are consistent with an exponential increase of (1.6 +/- 0.6)%/yr. This increase is discussed with regard to previous results and likely sources of CF4 at the ground. Further, it is shown that simultaneous measurements of N2O and CF4 provide a means of constraining the lower limit of the atmospheric lifetime of CF4 at least 2,300 years, two sigma. [less ▲]

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See detailTrends of OCS, HCN, SF6, CHClF2, (HCFC-22) in the lower stratosphere from 1985 and 1994 atmospheric trace molecule spectroscopy experiment measurements near 30 degrees N latitude
Rinsland, C. P.; Mahieu, Emmanuel ULg; Zander, Rodolphe ULg et al

in Geophysical Research Letters (1996), 23(17), 2349-2352

Volume mixing ratio (VMR) profiles of OCS, HCN, SF6, and CHClF2 (HCFC-22) have been measured near 30 degrees N latitude by the Atmospheric Trace Molecule Spectroscopy Fourier transform spectrometer during ... [more ▼]

Volume mixing ratio (VMR) profiles of OCS, HCN, SF6, and CHClF2 (HCFC-22) have been measured near 30 degrees N latitude by the Atmospheric Trace Molecule Spectroscopy Fourier transform spectrometer during shuttle flights on 29 April-6 May 1985 and 3-2 November 1994. The change in the concentration of each molecule in the lower stratosphere has been derived for this 9 1/2-year period by comparing measurements between potential temperatures of 395 to 800 K (similar to 17 to 30 km altitude) relative to simultaneously measured values of the long-lived tracer N2O. Exponential rates of increase inferred for 1985-to-1994 from these comparisons are (0.1 +/- 0.4)% yr(-1) for OCS, (1.0 +/- 1.0)% yr(-1) for HCN, (8.0+/-0.7)% yr(-1) for SF6, and (8.0 +/- 1.0)% yr(-1) for CHClF2 (HCFC-22), 1 sigma. The lack of an appreciable trend for OCS suggests the background (i.e., nonvolcanic) source of stratospheric aerosol was the same during the two periods. These results are compared with trends reported in the literature. [less ▲]

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See detailThe Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment: Deployment on the ATLAS Space Shuttle missions
Gunson, Michael R.; Abbas, M. M.; Abrams, M. C. et al

in Geophysical Research Letters (1996), 23(17), 2333-2336

The ATMOS Fourier transform spectrometer was flown for a fourth time on the Space Shuttle as part of the ATLAS-3 instrument payload in November 1994. More than 190 sunrise and sunset occultation events ... [more ▼]

The ATMOS Fourier transform spectrometer was flown for a fourth time on the Space Shuttle as part of the ATLAS-3 instrument payload in November 1994. More than 190 sunrise and sunset occultation events provided measurements of more than 30 atmospheric trace gases at latitudes 3-49 degrees N and 65-72 degrees S, including observations both inside and outside the Antarctic polar vortex. The instrument configuration, data retrieval methodology, and mission background are described to place in context analyses of ATMOS data presented in this issue. [less ▲]

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See detailAPRIL 1993 ARCTIC PROFILES OF STRATOSPHERIC HCL, CLONO2, AND CCL2F2 FROM ATMOSPHERIC TRACE MOLECULE SPECTROSCOPY ATLAS 2 INFRARED SOLAR OCCULTATION SPECTRA
Rinsland, C. P.; Gunson, M. R.; Abrams, M. C. et al

in Journal of Geophysical Research (1995), 100(D7), 14019-14027

Partitioning among the major components of the stratospheric odd chlorine family inside and outside of the remanent Arctic vortex has been studied on the basis of infrared solar occultation measurements ... [more ▼]

Partitioning among the major components of the stratospheric odd chlorine family inside and outside of the remanent Arctic vortex has been studied on the basis of infrared solar occultation measurements obtained by the atmospheric trace molecule spectroscopy (ATMOS) Fourier transform spectrometer during the ATLAS 2 shuttle mission (April 8-17, 1993). Profiles of hydrogen chloride (HCl) and simultaneous profiles of chlorine nitrate (ClONO2) and CFC-12 (CCl2F2) are reported for examples of in-vortex and out-of-vortex conditions. Increased ClONO2 volume-mixing ratios (VMRs) are measured in the vortex below 20 mbar (similar to 25 km altitude) with a peak ClONO2 VMR of 2.05 +/- 0.45 ppbv (10(-9) per volume) at 56 mbar (similar to 19 km altitude). The reported error correspond to la uncertainties. Simultaneous CCl2F2 and N2O measurements, combined with published empirical relations, indicate that only 0.34 +/- 0.15 ppbv, about 10% of total chlorine, was bound in organic species at the ClONO2 VMR peak in the vortex. A colocated vortex profile of HCl, referenced to simultaneous N2O VMR measurements, has been used to derive a HCl mixing ratio of 1.21 +/- 0.12 ppbv corresponding to the ClONO2 VMR peak. The internal consistency of the ATMOS measurements is demonstrated by the agreement between the total chlorine mixing ratio of 3.60 +/- 0.72 ppbv derived at the ClONO2 VMR peak in the vortex and HCl measurements of 3.37 +/- 0.37 and 3.76 +/- 0.41 ppbv at 0.56 mbar, where HCl is the only significant chlorine-bearing molecule. Outside the vortex the mixing ratio of HCl exceeds the mixing ratio of ClONO2 throughout the stratosphere. [less ▲]

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See detailGROUND-BASED INFRARED MEASUREMENTS OF CARBONYL SULFIDE TOTAL COLUMN ABUNDANCES - LONG-TERM TRENDS AND VARIABILITY
RINSLAND, C. P.; Zander, Rodolphe ULg; Mahieu, Emmanuel ULg et al

in Journal of Geophysical Research (1992), 97(D5), 5995-6002

Total vertical column abundances of carbonyl sulfide (OCS) have been derived from time series of high-resolution infrared solar absorption spectra recorded at the National Solar Observatory McMath solar ... [more ▼]

Total vertical column abundances of carbonyl sulfide (OCS) have been derived from time series of high-resolution infrared solar absorption spectra recorded at the National Solar Observatory McMath solar telescope facility on Kitt Peak (altitude 2.09 km, latitude 31.9-degrees-N, longitude 111.6-degrees-W), southwest of Tucson, Arizona, and at the International Scientific Station of the Jungfraujoch (altitude 3.58 km, latitude 46.5-degrees-N, longitude 8.0-degrees-E), in the Swiss Alps. The analysis of both data sets is based on nonlinear least squares spectral fittings of narrow intervals centered on lines of the intense nu-3 band of OCS, the P(37) transition at 2045.5788 cm-1 and the P(15) transition at 2055.8609 cm-1, with a consistent set of spectroscopic line parameters. The Kitt Peak measurements, recorded on 30 different days between May 1977 and March 1991, show a 10% peak-to-peak seasonal cycle with a summer maximum and a winter minimum and a trend in the total column abundance equal to (0.1 +/- 0.2)% yr-1, 2-sigma. Jungfraujoch solar spectra recorded on 67 different days between October 1984 and April 1991 have been analyzed. The fitted trend in the Jungfraujoch total columns, (-0.1 +/- 0.5)% yr-1, 2-sigma, is consistent with the Kitt Peak trend results within the errors. The Jungfraujoch total columns show a more complex seasonal variation than noted in the Kitt Peak data. The mean of the daily averaged total columns, 8.44 x 10(15) molecules cm-2 above Kitt Peak and 6.41 x 10(15) molecules cm-2 above the Jungfraujoch station, correspond respectively to mean tropospheric mixing ratios of 0.54 +/- 0.04 and 0.52 +/- 0.04 parts per billion by volume; these values are consistent with previously reported remote and in situ measurements. Taken together, the results from the two sites indicate that there has been no significant change in the OCS total column abundance at northern mid-latitudes over the last decade. [less ▲]

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