 |
| Titel |
Short-lived brominated hydrocarbons – observations in the source regions and the tropical tropopause layer |
| VerfasserIn |
S. Brinckmann, A. Engel, H. Bönisch, B. Quack, E. Atlas |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 12, no. 3 ; Nr. 12, no. 3 (2012-02-01), S.1213-1228 |
| Datensatznummer |
250010626
|
| Publikation (Nr.) |
 copernicus.org/acp-12-1213-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| 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
CHBr3, CH2Br2, CHBr2Cl and CH2BrCl 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
CHBr3 and CH2Br2. 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 CHBr3, CH2Br2, CHBrCl2,
CHBr2Cl and CH2BrCl. 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 CH2BrCl). 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
CHBr3/CH2Br2/CHBrCl2/CHBr2Cl. 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).
CH2Br2 (1.45 ppt) and CHBr3 (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 CH2Br2 and CHBr3, respectively. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|