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Dibromomethane (CH 2 Br 2 ) measurements at the upper troposphere and lower stratosphere
Author(s) -
Kourtidis Kostas,
Borchers Reinhard,
Fabian Peter
Publication year - 1996
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/96gl02438
Subject(s) - stratosphere , bromine , troposphere , tropopause , atmospheric sciences , altitude (triangle) , ozone , environmental science , chemistry , meteorology , physics , geometry , mathematics , organic chemistry
Stable brominated hydrocarbons, beside their role in the geochemical cycling of bromine, may enter the stratosphere, where they can efficiently catalyze ozone destruction through the release of inorganic bromine (Br y ). Three vertical profiles of dibromomethane (CH 2 Br 2 ) are reported here, derived from the analyses of air samples collected by the MPAE balloon‐borne cryogenic sampler at 17°N in 1990 and at 68°N in 1992 and 1995. Upper tropospheric volume tractions of this compound from below detection limit to 1.7 pptv were measured. Although CH 2 Br 2 was already below the detection limit at the tropopause during one of those flights, it was present in the first 2–4 km of the stratosphere in measurable quantities during the other two flights. Concurrent CH 3 Br and Halons 1211 (CBrClF 2 ) and 1301 (CBrF 3 ) measurements suggest that CH 2 Br 2 could contribute up to 20% of Br y released in this altitude region while it could deliver around 10% of the total bromine entering the stratosphere.