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| Titel |
Latitudinal distribution of reactive iodine in the Eastern Pacific and its link to open ocean sources |
| VerfasserIn |
A. S. Mahajan, J. C. Gómez Martín, T. D. Hay, S.-J. Royer, S. Yvon-Lewis, Y. Liu, L. Hu, C. Prados-Roman, C. Ordóñez, J. M. C. Plane, A. Saiz-Lopez |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 12, no. 23 ; Nr. 12, no. 23 (2012-12-05), S.11609-11617 |
| Datensatznummer |
250011649
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| Publikation (Nr.) |
 copernicus.org/acp-12-11609-2012.pdf |
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| Zusammenfassung |
| Ship-based Multi-Axis Differential Optical Absorption Spectroscopy
measurements of iodine monoxide (IO) and atmospheric and seawater Gas
Chromatography-Mass Spectrometer observations of methyl iodide (CH3I)
were made in the Eastern Pacific marine boundary layer during April 2010 as
a part of the HaloCarbon Air Sea Transect-Pacific (HaloCAST-P) scientific
cruise. The presence of IO in the open ocean environment was confirmed, with
a maximum differential slant column density of 5 × 1013 molecules cm−2
along the 1° elevation angle
(corresponding to approximately 1 pptv) measured in the oligotrophic region
of the Southeastern Pacific. Such low IO mixing ratios and their observed
geographical distribution are inconsistent with satellite estimates and with
previous understanding of oceanic sources of iodine. A strong correlation
was observed between reactive iodine (defined as IO + I) and CH3I,
suggesting common sources. In situ measurements of meteorological parameters
and physical ocean variables, along with satellite-based observations of
Chlorophyll a (Chl a) and Chromophoric Dissolved Organic Matter (CDOM) were
used to gain insight into the possible sources of iodine in this remote
environment. Surprisingly, reactive iodine showed a negative correlation
(> 99% confidence) to Chl a and CDOM across the cruise
transect. However, a significant positive correlation (> 99%
confidence) with sea surface temperature (SST) and salinity instead suggests
a widespread abiotic source related to the availability of aqueous iodine
and to temperature. |
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