Long-term trends in the concentrations of SF sub 6 , CHClF sub 2 , and COF sub 2 in the lower stratosphere from analysis of high-resolution infrared solar occultation spectra

Journal Article · Thu Sep 20 04:00:00 EDT 1990 · Journal of Geophysical Research; (USA)

OSTI ID:6061589

Rinsland, C P ^[1]; Goldman, A; Murcray, F J; Blatherwick, R D; Kosters, J J; Murcray, D G ^[2]; Sze, N D ^[3]; Massie, S T ^[4]

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1. NASA Langley Research Center, Hampton, VA (USA)
2. Univ. of Denver, CO (USA)
3. Atmospheric and Environmental Research Inc., Cambridge, MA (USA)
4. National Center for Atmospheric Research, Boulder, CO (USA)

The SF{sub 6} and CHClF{sub 2} results are based on spectra recorded by balloon-borne interferometers in March 1981 and June 1988 and a comparison of these results with the Atmospheric Trace Molecule Spectroscopy (ATMOS) Experiment/Spacelab 3 measurements obtained in May 1985 near 30{degree}N latitude. In the 13-18 km altitude range the mean measured SF{sub 6} mixing ratio in parts per trillion by volume (pptv) increased from 1.17 {plus minus} 0.21 in March 1981 to 2.02 {plus minus} 0.20 pptv in June 1988, and the CHClF{sub 2} mixing ratio below 15 km altitude increased from 51 {plus minus} 8 pptv in March 1981 to 102 {plus minus} 10 pptv in June 1988. The CHClF{sub 2} retrievals used new empirical CHClF{sub 2} line parameters derived from 0.03cm{sup {minus}1} resolution laboratory spectra recorded at six temperatures between 203 and 293 K; the derived mixing ratios are {approximately}30% higher than obtained with earlier sets of line parameters, thereby removing a large discrepancy noted previously between IR and in situ measurements of CHClF{sub 2}. Assuming an exponential growth model for fitting the trends, SF{sub 6} and CHClF{sub 2} mean increase rates of 7.4% {plus minus} 1.9% and 9.4% {plus minus} 1.3% year{sup {minus}1}, are obtained, respectively, which correspond to cumulative increases by factors of {approximately}1.7 and {approximately}2.0 in the concentrations of these gases over the 7.2-year measurement period. Analysis of spectra recorded in October 1979 and April 1989 yields COF{sub 2} volume mixing ratio that are respectively 0.44 {plus minus} 0.17 and 1.21 {plus minus} 0.24 times the ATMOS/Spacelab 3 values, from which an average COF{sub 2} increase rate of 10.3 {plus minus} 1.8% year{sup {minus}1} over this time period has been estimated. The model calculated trends are in reasonably good agreement with the observations.

• OSTI ID: 6061589
• Journal Information: Journal of Geophysical Research; (USA), Journal Name: Journal of Geophysical Research; (USA) Vol. 95:D10; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
ACCURACY
AIRSHIPS
ALTITUDE
ATMOSPHERIC CHEMISTRY
BALLOONS
CHEMISTRY
CHLORINATED ALIPHATIC HYDROCARBONS
EARTH ATMOSPHERE
ECOLOGICAL CONCENTRATION
FLUORIDES
FLUORINATED ALIPHATIC HYDROCARBONS
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HALOGENATED ALIPHATIC HYDROCARBONS
INFRARED SPECTRA
INTERFEROMETRY
MATHEMATICAL MODELS
MIXING
ONE-DIMENSIONAL CALCULATIONS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
RADIATIONS
SOLAR RADIATION
SPACE VEHICLES
SPECTRA
SPECTROSCOPY
STELLAR RADIATION
STRATOSPHERE
SULFUR COMPOUNDS
SULFUR FLUORIDES
VEHICLES