NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Collections About News Help Login
Back to Results
Mean Ages of Stratospheric Air Derived From in Situ Observations of CO2, CH4, and N2OAccurate mean ages for stratospheric air have been derived from a spatially and temporally comprehensive set of in situ observations of CO2, CH4, and N2O obtained from 1992 to 1998 from the NASA ER-2 aircraft and balloon flights. Errors associated with the tropospheric CO2 seasonal cycle and interannual variations in the CO2 growth rate are less than 0.5 year throughout the stratosphere and less than 0.3 year for air older than 2 years (N2O less than 275 ppbv), indicating that the age spectra are broad enough to attenuate these influences over the time period covered by these observations. The distribution of mean age with latitude and altitude provides detailed, quantitative information about the general circulation of the stratosphere. At 20 km, sharp meridional gradients in the mean age are observed across the subtropics. Between 20 and 30 km, the average difference in mean age between the tropics and midlatitudes is approximately 2 years, with slightly smaller differences at higher and lower altitudes. The mean age in the midlatitude middle stratosphere (approx. 25-32 km) is relatively constant with respect to altitude at 5 plus or minus 0.5 years. Comparison with earlier balloon observations of CO2 dating back to the 1970s indicates that the mean age of air in this region has remained within 11 year of its current value over the last 25 years. A climatology of mean age is derived from the observed compact relationship between mean age and N2O. These characteristics of the distribution of mean age in the stratosphere will serve as critically needed diagnostics for models of stratospheric transport.
Document ID
20020034734
Acquisition Source
Goddard Space Flight Center
Document Type
Preprint (Draft being sent to journal)
Authors
Andrews, A. E. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Boering, K. A. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Daube, B. C. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Wofsy, S. C. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Loewenstein, M. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Jost, H. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Podolske, J. R. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Webster, C. R. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Herman, R. L. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Scott, D. C. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Einaudi, Franco
Date Acquired
September 7, 2013
Publication Date
January 1, 2001
Subject Category
Environment Pollution
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Related Records

There are no records associated with this record.
No Preview Available