 |
| Titel |
Iodine emissions from the sea ice of the Weddell Sea |
| VerfasserIn |
H. M. Atkinson, R.-J. Huang, R. Chance, H. K. Roscoe, C. Hughes, B. Davison, A. Schönhardt, A. S. Mahajan, A. Saiz-Lopez, T. Hoffmann, P. S. Liss |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 12, no. 22 ; Nr. 12, no. 22 (2012-11-27), S.11229-11244 |
| Datensatznummer |
250011626
|
| Publikation (Nr.) |
 copernicus.org/acp-12-11229-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| Iodine compounds were measured above, below and within the sea ice of the
Weddell Sea during a cruise in 2009, to make progress in elucidating the
mechanism of local enhancement and volatilisation of iodine. I2 mixing
ratios of up to 12.4 pptv were measured 10 m above the sea ice, and up to
31 pptv was observed above surface snow on the nearby Brunt Ice Shelf – large
amounts. Atmospheric IO of up to 7 pptv was measured from the ship, and the
average sum of HOI and ICl was 1.9 pptv. These measurements confirm the
Weddell Sea as an iodine hotspot. Average atmospheric concentrations of
CH3I, C2H5I, CH2ICl, 2-C3H7I, CH2IBr and
1-C3H7I were each 0.2 pptv or less. On the Brunt Ice Shelf,
enhanced concentrations of CH3I and C2H5I (up to 0.5 and 1 pptv respectively) were observed in firn air, with a diurnal profile that
suggests the snow may be a source. In the sea ice brine, iodocarbons
concentrations were over 10 times those of the sea water below. The sum of
iodide + iodate was depleted in sea ice samples, suggesting some missing
iodine chemistry. Flux calculations suggest I2 dominates the iodine
atom flux to the atmosphere, but models cannot reconcile the observations
and suggest either a missing iodine source or other deficiencies in our
understanding of iodine chemistry. The observation of new particle
formation, consistent with the model predictions, strongly suggests an
iodine source. This combined study of iodine compounds is the first of its
kind in this unique region of sea ice rich in biology and rich in iodine
chemistry. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|