Abstract:
The isotopic composition of stratospheric water vapor is used as a tracer for the convective history of air injected into the stratosphere. Stratospheric profiles of HDO, H<sub>2</sub>O,CH<sub>3</sub>D, and CH<sub>4</sub> fro the ATMOS instrument, obtained over four missions from 1985-1994, are used to determine the initial deuterium-to-hydrogen ration of water vapor entering the stratosphere. We find that the initial DeltaD of stratospheric water is - 680 ± 80 (68 percent loss of deuterium), consistent with extrapolations from previous measurements at higher altitudes.
