Stratospheric Lifetimes of CFC-12, CCl4, CH4, CH3CL and N20 from Measurements Made By The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer

Authors

A. T. Brown
C. M. Volk
M. R. Schoebert
C. D. Boone
P. F. Bernath, Old Dominion UniversityFollow

Document Type

Article

Publication Date

2013

DOI

10.5194/acp-13-6921-2013

Publication Title

Atmospheric Chemistry and Physics

Volume

13

Issue

14

Pages

6921-6950

Abstract

Long lived halogen-containing compounds are important atmospheric constituents since they can act both as a source of chlorine radicals, which go on to catalyse ozone loss, and as powerful greenhouse gases. The long-term impact of these species on the ozone layer is dependent on their stratospheric lifetimes. Using observations from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) we present calculations of the stratospheric lifetimes of CFC-12, CCl₄, CH₄, CH₃Cl and N₂O. The lifetimes were calculated using the slope of the tracer-tracer correlation of these species with CFC-11 at the tropopause. The correlation slopes were corrected for the changing atmospheric concentrations of each species based on age of air and CFC-11 measurements from samples taken aboard the Geophysica aircraft - along with the effective linear trend of the volume mixing ratio (VMR) from tropical ground based AGAGE (Advanced Global Atmospheric Gases Experiment) sites. Stratospheric lifetimes were calculated using a CFC-11 lifetime of 45 yr. These calculations produced values of 113 + (-) 26 (18) yr (CFC-12), 35 + (-) 11 (7) yr (CCl₄), 69 + (-) 65 (23) yr (CH₃Cl), 123 + (-) 53 (28) yr (N₂O) and 195 + (-) 75 (42) yr (CH₄). The errors on these values are the weighted 1 sigma non-systematic errors. Systematic errors were estimated by recalculating lifetimes using VMRs which had been modified to reflect differences between ACE-FTS retrieved VMRs and those from other instruments. The results of these calculations, including systematic errors, were as follows: 113 + (-) 32 (20) for CFC-12, 123 + (-) 83 (35) for N₂O, 195 + (-) 139 (57) for CH₄, 35 + (-) 14 (8) for CCl₄ and 69 + (-) 2119 (34) yr for CH₃Cl. For CH₃Cl & CH₄ this represents the first calculation of the stratospheric lifetime using data from a space based instrument.

Original Publication Citation

Brown, A. T., Volk, C. M., Schoeberl, M. R., Boone, C. D., & Bernath, P. F. (2013). Stratospheric lifetimes of CFC-12, CCl₄, CH₄, CH₃Cl and N₂O from measurements made by the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS). Atmospheric Chemistry and Physics, 13(14), 6921-6950. doi: 10.5194/acp-13-6921-2013

ORCID

0000-0002-1255-396X (Bernath)

Repository Citation

Brown, A. T.; Volk, C. M.; Schoebert, M. R.; Boone, C. D.; and Bernath, P. F., "Stratospheric Lifetimes of CFC-12, CCl4, CH4, CH3CL and N20 from Measurements Made By The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer" (2013). Chemistry & Biochemistry Faculty Publications. 24.
https://digitalcommons.odu.edu/chemistry_fac_pubs/24