Measurements of CO in the upper troposphere and lower stratosphere
Abstract
In situ measurements of CO were made in the upper troposphere and lower stratosphere (7–21 km altitude) with the Jet Propulsion Laboratory (JPL) Aircraft Laser Infrared Absorption Spectrometer (ALIAS) on 58 flights of the NASA ER-2 aircraft from October 1995 through September 1997, between 90°N and 3°S latitude. Measured upper tropospheric CO was variable and typically ranged between 55 and 115 ppb, except for higher values over Alaska during summer 1997. Tropical stratospheric CO ranged from 58 ± 5 ppb at the tropopause to 12 ± 2 ppb above 20 km, having similar profiles in all seasons of the year. The tropical profile is reproduced by a simple Lagrangian box model of tropical ascent using measured CH4 and OH concentrations, Cl and O(^1D) concentrations from a photochemical model, and diabatic heating rates from a radiative heating model. From measured CO, quasi-horizontal mixing between the tropical and mid-latitude lower stratosphere is inferred to be rapid in the region between 400 K and 450 K potential temperature (altitudes less than 20 km).
Additional Information
© 1999 Elsevier Science Ltd. Received 16 April 1998; accepted 15 September 1998. We thank J.P. Pinto, S.C. Wofsy, and two anonymous reviewers for helpful comments; B.L. Gary for providing tropopause heights; E.J. Hintsa and E.M. Weinstock for H_(2)O data; K.H. Rosenlof for providing tropical heating rates; G.J. Flesch, L. Kroll, K. Modarress, and M. Tuchscherer for laboratory and field support of the ALIAS instrument; J.W. Elkins and R. Myers for gas standards; the ER-2 pilots and crew; and A.E. Kulawik for computational assistance. This work was supported by NASA's Upper Atmospheric Research Program (UARP) and the Atmospheric Effects of Aviation Project (AEAP). Part of the research described in this paper was carried out by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Division of Geological and Planetary Sciences, California Institute of Technology, Contribution 5764.Additional details
- Eprint ID
- 46506
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- CaltechAUTHORS:20140625-113609378
- NASA/JPL/Caltech
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2014-06-25Created from EPrint's datestamp field
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2021-11-10Created from EPrint's last_modified field
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- Division of Geological and Planetary Sciences
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- Caltech Division of Geological and Planetary Sciences
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- 5764