Far infrared remote sounding of stratospheric temperature and trace gas distributions

Limb thermal emission spectra of the earth's stratosphere in the far‐infrared spectral region, obtained as part of the Balloon Intercomparison Campaign (BIC), have been analyzed for retrieval of trace constituent distributions. The observations analyzed here were made with a balloon‐borne high‐resolution Michelson interferometer operating in the 20–100 cm−1 region, with an unapodized spectral resolution of 0.0033 cm−1. In this paper the vertical profiles of O3, H2O, and HDO retrieved from the observed spectra are presented and compared with the results from other BIC experiments. The retrieved profiles are found to be in good agreement with other measurements. The measurement of the HDO profile provides information about the sources of stratospheric water vapor. The variation of the D/H ratio of water vapor is derived from an analysis of HDO and H2O lines observed in the far‐infrared spectra and is compared with the available measurements in the literature.

Section: Experimental Techniquementioning

confidence: 98%

mentioning

confidence: 99%

Stratospheric O₃, H₂O, and HDO distributions from balloon‐based far‐infrared observations

Abbas

Guo

Carli³

et al. 1987

“…The radiative transfer model and the inversion technique employed here for spectral analysis have been discussed in detail in previous publications [Abbas et al, 1981[Abbas et al, , 1984a[Abbas et al, , 1985a; the brief review given here focuses on retrieval of the results presented in this paper. The monochromatic spectral intensity from a nonscattering atmosphere received at the observer height z0 at an angle 00 is…”

Section: Radiative Transfer Modelmentioning

confidence: 99%

Simultaneous measurement of stratospheric O₃, H₂O, CH₄, and N₂O profiles from infrared limb thermal emissions

Abbas¹,

Glenn²,

Kunde³

et al. 1987

Thermal emission measurements of the earth's stratospheric limb were made with a cryogenically cooled high‐resolution Michelson interferometer on a balloon flight launched from Palestine, Texas, on November 6, 1984. Infrared spectra for complete limb sequences were obtained over portions of the 700–1940 cm−1 range with an unapodized spectral resolution of 0.03 cm−1 for tangent heights varying from 13 to 39 km. The observed data from 1125 to 1425 cm−1 have been analyzed for simultaneous measurement of O3, H2O, CH4, and N2O profiles. The analysis employs line‐by‐line and layer‐by‐layer radiative transfer calculations, including curvature and refraction effects. The optimum use of geometric and spectral effects is made to obtain sharply peaked weighting functions. Contributions from stratospheric aerosol are included by measuring the light extinction within the window regions of the observed spectra. The retrieved constituent profiles are compared with measurements made with a variety of techniques by other groups. The comparison shows good agreement with the published data for all gases, indicating the capability of retrieving trace gas profiles from high‐resolution thermal emission limb measurements.

“…Rinsland et al [1985] have analyzed solar absorption measurements in the 10-#m band made by Brault [1979] at the National Solar Observatory at Kitt Peak, and retrieved total column densities of the two isomers of heavy ozone. Their results indicated only marginally statistically significant enhancements in the column abundances by a factor of 1. cm-1 region selected for good signal-to-noise ratios were analyzed separately for retrieval of the vertical profiles of heavy ozone employing techniques developed for analysis of highresolution thermal emission spectra, described in detail in previous publications [see Abbas et al, 1981Abbas et al, , 1984aAbbas et al, , 1984bAbbas et al, , 1985Abbas et al, , 1987a. A brief review of these techniques relevant to the results of this paper is given here for convenience.…”

mentioning

confidence: 99%

Heavy ozone distribution in the stratosphere from far‐infrared observations

Abbas¹,

Guo²,

Carli³

et al. 1987

The distribution of isotopically heavy ozone in the stratosphere has been obtained from an analysis of balloon-based high-resolution thermal emission spectra in the far infrared. The mixing ratio profiles of 160160180 and 160180160, retrieved from inversion of several limb sequences of a number of spectral lines in the 39-76 cm -• region, indicate enhancements over the expected values in the 25-to 37-km altitude range. The ratio of total heavy isotopic ozone 500 3 to normal '•80 3 shows enhancements of •45% at 37 km, decreasing to a minimum of ~ 13% at --29 km, and increasing to ~ 18% at 25 km. The results from this work are compared with Mauersberger's (1987) in situ mass spectrometer measurements. INTRODUCTION Isotopic ratios of atoms or molecules often provide valuable information about the past or presently occurring processes inmany branches of science, including astrophysics, geophysics, and atmospheric physics. The isotopic composition of several constituents in the Earth's atmosphere is known to be different from the statistical values on the Earth's surface. The reasons for this isotopic fractionation are diverse and provide information about the chemical and physical processes in the atmosphere. A detailed review of our current understanding of the mechanisms leading to isotopic fractionation in planetary atmospheres has been given by Kaye [1987]. An interest in the problem of photochemical processes controlling the distribution of atmospheric ozone naturally extends to the distribution of ozone isotopes. Heavy ozone is formed in the stratosphere by the reactions and 340 3 --[-hv-• 260 + 280 180 '•-320 2 -•-M • 500 3 -•-M 160-•-340 2 -•-M • 500 3 -•-M (1) (2a) (2b) The suggestion that stratospheric heavy ozone is enhanced owing to the enrichment of 280 produced by a higher photodissociation rate of 340 2 in the Schumman-Runge bands was first made by Cicerone and McCrumb [1980, p. 252]. This suggestion, however, has been contested on two separate bases. First, Kaye and Strobel [1983] and Kaye [1986] have argued that stratospheric heavy ozone concentration depends on the relative time scales for odd oxygen production, destruction, and interconversion, and since the exchange reaction (3 18 0 -•-3202 • 16 0 -•-3402