INCREASE IN ATMOSPHERIC CHF2CL(HCFC-22) OVER SOUTHERN CALIFORNIA FROM 1985 TO 1990

Column densities of CHF2Cl (HCFC-22) have been measured over Table Mountain Facility (TMF), Wrightwood, California (34.4-degrees-N) using the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier-transform infrared (FTIR) spectrometer. Between October 1985 and July 1990, the exponential column increase rate was (6.7+/-0.5)% yr-1 Additionally, column measurements of CHF2Cl over McMurdo Sound, Antarctica (78-degrees-S) in September and October 1986 by the MarkIV FTIR spectrometer were used to derive a south-north interhemispheric ratio of (0.86+/-0.08). Model calculations investigated the feasibility of using CHF2Cl column measurements with a predicted global OH field to determine a globally averaged chemical lifetime for CHF2Cl, or equivalently, an estimate of the OH field using a predicted lifetime. The current uncertainty in historical CHF2Cl emissions is too large for CHF2Cl to be used to infer adequately either the lifetime or the OH field.