Stratospheric Trace Gas Composition Studies Utilizing in situ Cryogenic, Whole-Air Sampling Methods

摘要

A balloon borne cryogenic whole air sampler (tri-sampler) is used to obtain one-mole sample quantities at each of three altitudes on a single flight. Samples have been obtained at six altitudes from 12 to 30 km at each of five latitudes from 9 deg N to 64 deg N. The samples are maintained frozen until just prior to analysis; chemiluminescence and gas chromatography techniques are used to determine mixing ratios of NO, NO2, N2O, CFC13 and CF2C12. Variations in mixing ratios with altitude and latitude have been noted, but no variations with time within the stratosphere have been detected over the five-year duration of the flights. Gas calibration procedures include two dynamic dilution methods and one permeation tube method, with close agreement among the methods being noted. (Author)