Vertical transport rates in the stratosphere in 1993 from observations or CO2, N2O and CH4

Measurements of CO2, N2O and CH4 are analyzed to define hemispheric average vertical exchange rates in the lower stratosphere from November 1992 to October 1993. Effective vertical diffusion coefficients were small in summer, ≤ 1 m²s−1 at altitudes below 25 km; values were similar near the tropopause in winter, but increased markedly with altitude. The analysis suggests possibly longer residence times for exhaust from stratospheric aircraft, and more efficient transport from 20 km to the middle stratosphere, than predicted by many current models. Seasonally-resolved measurements of stratospheric CO2 and N2O provide significant new constraints on rates for global-scale vertical transport.

[1]  S. Solomon,et al.  Measurements of halogenated organic compounds near the tropical tropopause , 1993 .

[2]  Mark R. Schoeberl,et al.  NEw observations of the NOy/N2O correlation in the lower stratosphere , 1993 .

[3]  M. Prather,et al.  Simulations of the trend and annual cycle in stratospheric CO2 , 1993 .

[4]  Malcolm K. W. Ko,et al.  Interrelationships between mixing ratios of long‐lived stratospheric constituents , 1992 .

[5]  D. Hartmann,et al.  The dynamics of the stratospheric polar vortex and its relation to springtime ozone depletions. , 1991, Science.

[6]  S. Solomon,et al.  A diagnostic for denitrification in the winter polar stratospheres , 1990, Nature.

[7]  P. Tans,et al.  Atmospheric carbon dioxide measurements in the remote global troposphere, 1981-1984 , 1988 .

[8]  R. A. Plumb,et al.  The Zonally Averaged Transport Characteristics of the GFDL General Circulation/Transport Model , 1987 .

[9]  H. Levy,et al.  Three‐dimensional simulations of stratospheric N2O: Predictions for other trace constituents , 1986 .

[10]  J. Holton.  A dynamically based transport parameterization for one-dimensional photochemical models , 1986 .

[11]  D. Ehhalt,et al.  On the temporal variance of stratospheric trace gas concentrations , 1983 .

[12]  D. Albritton,et al.  Correction [of “Atmospheric N2O mixing‐ratio data”] , 1981 .

[13]  D. Albritton,et al.  Stratospheric CFCl3, CF2Cl2, and N2O height profile measurements at several latitudes , 1980 .

[14]  S. Wofsy,et al.  On vertical mixing in the upper stratosphere and lower mesosphere , 1973 .

[15]  F. S. Johnson,et al.  Eddy diffusion and oxygen transport in the lower thermosphere , 1965 .

[16]  H. Lettau.  Diffusion in the Upper Atmosphere , 1951 .