Wofsy, S.C., K.A. Boering, B. Daube, M.B. McElroy, M. Loewenstein, J. Podolske, J.W. Elkins, G. Dutton, and D. Fahey (1994), Vertical Transport Rates in 1993 From Observations of CO2, N2O and Ch4, Geophys. Res. Lett., 21, 2571-2574.