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Titel |
An instrument for measurements of BrO with LED-based Cavity-Enhanced Differential Optical Absorption Spectroscopy |
VerfasserIn |
D. J. Hoch, J. Buxmann, H. Sihler, D. Pöhler, C. Zetzsch, U. Platt |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1867-1381
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Measurement Techniques ; 7, no. 1 ; Nr. 7, no. 1 (2014-01-27), S.199-214 |
Datensatznummer |
250115567
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Publikation (Nr.) |
copernicus.org/amt-7-199-2014.pdf |
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Zusammenfassung |
The chemistry of the troposphere and specifically the global tropospheric
ozone budget is affected by reactive halogen species such as bromine monoxide
(BrO) or chlorine monoxide (ClO). Especially BrO plays an important role in
the processes of ozone destruction, disturbance of NOx and
HOx chemistry, oxidation of dimethyl sulfide (DMS), and the deposition of elementary
mercury. In the troposphere BrO has been detected in polar regions, at salt
lakes, in volcanic plumes, and in the marine boundary layer. For a better
understanding of these processes, field measurements as well as
reaction chamber studies are performed. In both cases instruments with high
spatial resolution and high sensitivity are necessary. A Cavity-Enhanced Differential Optical Absorption Spectroscopy (CE-DOAS) instrument with an
open path measurement cell was designed and applied. For the first time, a
CE-DOAS instrument is presented using an UV LED in the 325–365 nm
wavelength range. In laboratory studies, BrO as well as HONO, HCHO, O3,
and O4 could be reliably determined at detection limits of 20 ppt for
BrO, 9.1 ppb for HCHO, 970 ppt for HONO, and 91 ppb for O3, for five
minutes integration time. The best detection limits were
achieved for BrO (11 ppt), HCHO (5.1 ppb), HONO (490 ppt), and O3
(59 ppb) for integration times of 81 minutes or less. Comparison with
established White system (WS) DOAS and O3 monitor measurements demonstrate the
reliability of the instrument. |
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