Open AccessChlorine budget and partitioning during the Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment (SOLVE)
Author(s) -
Schauffler S. M.,
Atlas E. L.,
Donnelly S. G.,
Andrews A.,
Montzka S. A.,
Elkins J. W.,
Hurst D. F.,
Romashkin P. A.,
Dutton G. S.,
Stroud V.
Publication year - 2003
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2001jd002040
Subject(s) - chlorine , stratosphere , ozone , mixing ratio , chemistry , ozone depletion , troposphere , aerosol , ozone layer , environmental chemistry , atmospheric sciences , organic chemistry , physics
The amount of chlorine in the stratosphere has a direct influence on the magnitude of chlorine‐catalyzed ozone loss. A comprehensive suite of organic source gases of chlorine in the stratosphere was measured during the NASA Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment (SOLVE) campaign in the arctic winter of 2000. Measurements included chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halon 1211, solvents, methyl chloride, N 2 O, and CH 4 . Inorganic chlorine contributions from each compound were calculated using the organic chlorine measurements, mean age of air, tropospheric trends, and a method to account for mixing in the stratosphere. Total organic chlorine measured at tropospheric levels of N 2 O was on the order of 3500 ppt. Total calculated inorganic chlorine at a N 2 O mixing ratio of 50 ppb (corresponding to a mean age of 5.5 years) was on the order of 3400 ppt. CFCs were the largest contributors to total organic chlorine (55–70%) over the measured N 2 O range (50–315 ppb), followed by CH 3 Cl (15%), solvents (5–20%), and HCFCs (5–25%). CH 3 Cl contribution was consistently about 15% across the organic chlorine range. Contributions to total calculated inorganic chlorine at 50 ppb N 2 O were 58% from CFCs, 24% from solvents, 16% from CH 3 Cl, and 2% from HCFCs. Updates to fractional chlorine release values for each compound relative to CFC 11 were calculated from the SOLVE measurements. An average value of 0.58 was calculated for the fractional chlorine release of CFC 11 over the 3–4 year mean age range, which was lower than the previous value of 0.80. The fractional chlorine release values for HCFCs 141b and 142b relative to CFC 11 were significantly lower than previous calculations.