A global inventory of stratospheric chlorine in 2004
Artikel i vetenskaplig tidskrift, 2006

Total chlorine (CITOT) in the stratosphere has been determined using the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) measurements of HCl, ClONO2, CH3Cl, CCl4, CCl3F (CFC-11), CCl2F2 (CFC-12), CHClF2 (HCFC-22), CCl2FCClF2 (CFC-113), CH3CClF2 (HCFC-142b), COClF, and ClO supplemented by data from several other sources, including both measurements and models. Separate chlorine inventories were carried out in five latitude zones (60°-82°N, 30°-60°N, 30°S-30°N, 30°-60°S, and 60°-82°S), averaging the period of February 2004 to January 2005 inclusive, when possible, to deal with seasonal variations. The effect of diurnal variation was avoided by only using measurements taken at local sunset. Mean stratospheric ClTOT values of 3.65 ppbv were determined for both the northern and southern midlatitudes (with an estimated 1σ, accuracy of ±0.13 ppbv and a precision of ±.09 ppbv), accompanied by a slightly lower value in the tropics and slightly higher values at high latitudes. Stratospheric ClTOT profiles in all five latitude zones are nearly linear with a slight positive slope in ppbv /km. Both the observed slopes and pattern of latitudinal variation can be interpreted as evidence of the beginning of a decline in global stratospheric chlorine, which is qualitatively consistent with the mean stratospheric circulation pattern and time lag necessary for transport.


R. Nassar

Harvard University

University of Waterloo

P. F. Bernath

University of Waterloo

C. D. Boone

University of Waterloo

C. Clerbaux

Universite Pierre et Marie Curie

Université libre de Bruxelles (ULB)

P. F. Coheur

Université libre de Bruxelles (ULB)

G. Dufour

Laboratoire de Meteorologie Dynamique Ecole Polytechnique

L. Froidevaux

Jet Propulsion Laboratory, California Institute of Technology

E. Mahieu

Universite de Liege

J. C. McConnell

York University

S. D. McLeod

University of Waterloo

Donal Murtagh

Chalmers, Institutionen för radio- och rymdvetenskap

C. P. Rinsland

NASA Langley Research Center

K. Semeniuk

York University

R. Skelton

University of Waterloo

K. A. Walker

University of Waterloo

University of Toronto

R. Zander

Universite de Liege

Journal of Geophysical Research

0148-0227 (ISSN)

Vol. 111


Rymd- och flygteknik