Vertical transport rates in the stratosphere in 1993 from observations or CO2, N2O and CH4
Abstract
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.
- Publication:
-
Geophysical Research Letters
- Pub Date:
- November 1994
- DOI:
- Bibcode:
- 1994GeoRL..21.2571W
- Keywords:
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- Air Pollution;
- Air Sampling;
- Atmospheric Chemistry;
- Carbon Dioxide;
- Gaseous Diffusion;
- Meteorology;
- Methane;
- Nitrogen Oxides;
- Rates (Per Time);
- Stratosphere;
- Vertical Distribution;
- Atmospheric Models;
- Chemical Reactions;
- Civil Aviation;
- Exhaust Emission;
- Gas Exchange;
- Pollution Monitoring;
- Transport Aircraft;
- Atmospheric Composition and Structure: Middle atmosphere-composition and chemistry