Tracer-tracer relationships and lower stratospheric dynamics: CO2 and N2O correlations during SPADE
Abstract
Simultaneous measurements of CO2 and N2O from the NASA ER-2 aircraft during SPADE deployments in November 1992, April/May 1993, and October 1993 provide new information on transport rates in the lower stratosphere. The tropospheric seasonal cycle in CO2, superimposed on the long-term trend, is observed to propagate into the stratosphere. The compact correlations observed between CO2 and N2O indicate that meridional transport is sufficiently rapid to create a uniform set of relationships over the northern hemisphere up to at least 21 km even though CO2 changes significantly on a time scale of 8 to 12 weeks. The observed seasonal dependence of the correlations indicates that vertical transport above 20 km is slower in northern summer than in winter and slow throughout the year between 19 km and the tropopause. The inferred amplitude of the seasonal CO2 oscillation in the stratosphere, viewed relative to N2O, places constraints on the mean latitude for air entering the stratosphere.
- Publication:
-
Geophysical Research Letters
- Pub Date:
- November 1994
- DOI:
- Bibcode:
- 1994GeoRL..21.2567B
- Keywords:
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- Air Sampling;
- Atmospheric Chemistry;
- Atmospheric Circulation;
- Carbon Dioxide;
- Cross Correlation;
- Gas Dynamics;
- Meteorology;
- Nitrogen Oxides;
- Stratosphere;
- Annual Variations;
- Concentration (Composition);
- Earth Resources Survey Aircraft;
- Rates (Per Time);
- Transport Properties;
- Vertical Distribution;
- Atmospheric Composition and Structure: Middle atmosphere-composition and chemistry