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| Titel |
The "inorganic" iodine source in the marine environment: experimental and modelling studies |
| VerfasserIn |
S. M. MacDonald, L. J. Carpenter, M. D. Shaw, R. Kumar, J. M. C. Plane |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250066789
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| Zusammenfassung |
| Reactive iodine species in the marine boundary layer can have a significant effect on the
lifetime of oxidising species in the lower atmosphere by causing ozone destruction
and altering the HOx and NOx balance, and can also contribute to new particle
production through the formation of iodine oxides. Over the remote oceans organo-iodine
compounds contribute to the atmospheric iodine budget; however, these compounds do
not fully account for the IO concentrations observed, where an additional source
appears to be required. The deposition of O3 to the sea surface and subsequent
reaction with iodide in the interfacial layer has been proposed as the missing source of
reactive iodine to the marine boundary layer. Experiments were conducted to quantify
the flux of reactive iodine produced from this process, which releases both I2 and
HOI into the gas phase. The inorganic iodine flux was investigated as a function of
temperature, iodide concentration, ozone concentration, salinity, turbulence and
organic species. The results were modelled using a kinetic model of the interfacial
layer of the sea surface, and a parameterised function of the iodine flux was then
derived. Finally, a 1-D chemistry/transport model of the marine boundary layer, using
this source function together with the measured organo-iodine flux, predicts IO
concentrations over the tropical Atlantic ocean in good agreement with observations. |
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