Short-lived brominated hydrocarbons – observations in the source regions and the tropical tropopause layer
Item
Title (Dublin Core)
Short-lived brominated hydrocarbons – observations in the source regions and the tropical tropopause layer
Description (Dublin Core)
We conducted measurements of the five important short-lived organic bromine species in the marine boundary layer (MBL). Measurements were made in the Northern Hemisphere mid-latitudes (Sylt Island, North Sea) in June 2009 and in the tropical Western Pacific during the TransBrom ship campaign in October 2009. For the one-week time series on Sylt Island, mean mixing ratios of CHBr<sub>3</sub>, CH<sub>2</sub>Br<sub>2</sub>, CHBr<sub>2</sub>Cl and CH<sub>2</sub>BrCl were 2.0, 1.1, 0.2, 0.1 ppt, respectively. We found maxima of 5.8 and 1.6 ppt for the two main components CHBr<sub>3</sub> and CH<sub>2</sub>Br<sub>2</sub>. Along the cruise track in the Western Pacific (between 41° N and 13° S) we measured mean mixing ratios of 0.9, 0.9, 0.2, 0.1 and 0.1 ppt for CHBr<sub>3</sub>, CH<sub>2</sub>Br<sub>2</sub>, CHBrCl<sub>2</sub>, CHBr<sub>2</sub>Cl and CH<sub>2</sub>BrCl. Air samples with coastal influence showed considerably higher mixing ratios than the samples with open ocean origin. Correlation analyses of the two data sets yielded strong linear relationships between the mixing ratios of four of the five species (except for CH<sub>2</sub>BrCl). Using a combined data set from the two campaigns and a comparison with the results from two former studies, rough estimates of the molar emission ratios between the correlated substances were: 9/1/0.35/0.35 for CHBr<sub>3</sub>/CH<sub>2</sub>Br<sub>2</sub>/CHBrCl<sub>2</sub>/CHBr<sub>2</sub>Cl. Additional measurements were made in the tropical tropopause layer (TTL) above Teresina (Brazil, 5° S) in June 2008, using balloon-borne cryogenic whole air sampling technique. Near the level of zero clear-sky net radiative heating (LZRH) at 14.8 km about 2.25 ppt organic bromine was bound to the five short-lived species, making up 13% of total organic bromine (17.82 ppt). CH<sub>2</sub>Br<sub>2</sub> (1.45 ppt) and CHBr<sub>3</sub> (0.56 ppt) accounted for 90% of the budget of short-lived compounds in that region. Near the tropopause (at 17.5 km) organic bromine from these substances was reduced to 1.35 ppt, with 1.07 and 0.12 ppt attributed to CH<sub>2</sub>Br<sub>2</sub> and CHBr<sub>3</sub>, respectively.
Creator (Dublin Core)
Brinckmann, S.
Engel, A.
Bönisch, H.
Quack, B.
Atlas, E.
Date (Dublin Core)
2018-01-15
Type (Dublin Core)
info:eu-repo/semantics/Text
Format (Dublin Core)
info:eu-repo/semantics/application/pdf
Identifier (Dublin Core)
10.5194/acp-12-1213-2012
https://acp.copernicus.org/articles/12/1213/2012/
Source (Dublin Core)
eISSN: 1680-7324
Language (Dublin Core)
eng
Relation (Dublin Core)
info:eu-repo/grantAgreement/EC/FP7/226224
Rights (Dublin Core)
info:eu-repo/semantics/openAccess
