ISSN:
1573-0662
Keywords:
Arctic
;
analytical method
;
boundary layer
;
bromine oxide
;
chemical amplification
;
chlorine oxide
;
field measurement
;
halogens
;
ozone depletion
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Geosciences
Notes:
Abstract Chemical amplification, CA, a method commonly used for the detection of peroxy radicals, HO2 and RO2, was found to be sensitive towards ClOx (Cl+ClO+OClO) as well. ClOx is reduced by NO to Cl atoms which react with carbon monoxide in the presence of O2. The reaction sequence thus initiated oxidizes CO to CO2 and NO to NO2, with a chain length of 300 ± 60. This allows the atmospheric ClOx content to be measured under ambient conditions with a detection limit of better than 1 ppt. In parallel peroxy radicals are indicated with a chain length of 160 ± 15. Chemical amplification is not specific and does not indicate which radical chain it is seeing. Identification relies solely on plausibility. During the ARCtic Tropospheric Ozone Chemistry (ARCTOC) campaign in spring 1995 and 1996 the CA technique was used at Ny-Ålesund. ClOx at mixing ratios of up to 2 ppt were found in the boundary layer under certain conditions. The low concentrations of ClOx indicate that the arctic boundary ozone depletion is mainly driven by bromine.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1006208828324
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