Methyl iodide production in the open ocean
Production pathways of the prominent volatile organic halogen compound methyl iodide (CH<sub>3</sub>I) are not fully understood. Based on observations, production of CH<sub>3</sub>I via photochemical degradation of organic material <i>or</i> via phytoplankton prod...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-08-01
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| Series: | Biogeosciences |
| Online Access: | http://www.biogeosciences.net/11/4459/2014/bg-11-4459-2014.pdf |
| _version_ | 1818852628711342080 |
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| author | I. Stemmler I. Hense B. Quack E. Maier-Reimer |
| author_facet | I. Stemmler I. Hense B. Quack E. Maier-Reimer |
| author_sort | I. Stemmler |
| collection | DOAJ |
| description | Production pathways of the
prominent volatile organic halogen compound methyl iodide (CH<sub>3</sub>I) are not
fully understood. Based on observations, production of CH<sub>3</sub>I via
photochemical degradation of organic material <i>or</i> via phytoplankton
production has been proposed. Additional insights could not be gained from
correlations between observed biological and environmental variables or from
biogeochemical modeling to identify unambiguously the source of methyl iodide. In this study, we aim to
address this question of source mechanisms with a three-dimensional global
ocean general circulation model including biogeochemistry
(MPIOM–HAMOCC (MPIOM – Max Planck Institute Ocean Model HAMOCC –
HAMburg Ocean Carbon Cycle model)) by carrying out a series of
sensitivity experiments. The simulated fields are compared with a newly
available global data set. Simulated distribution patterns and emissions of
CH<sub>3</sub>I differ largely for the two different production pathways. The
evaluation of our model results with observations shows that, on the global
scale, observed surface concentrations of CH<sub>3</sub>I can be best explained
by the photochemical production pathway. Our results further emphasize that
correlations between CH<sub>3</sub>I and abiotic or biotic factors do not necessarily
provide meaningful insights concerning the source of origin. Overall, we find
a net global annual CH<sub>3</sub>I air–sea flux that ranges between 70 and
260 Gg yr<sup>−1</sup>. On the global scale, the ocean acts as a net source of
methyl iodide for the atmosphere, though in some regions in boreal winter,
fluxes are of the opposite direction (from the atmosphere to the ocean). |
| first_indexed | 2024-12-19T07:23:57Z |
| format | Article |
| id | doaj.art-8e244bb518074c86accceb6a7464cb2e |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-12-19T07:23:57Z |
| publishDate | 2014-08-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-8e244bb518074c86accceb6a7464cb2e2022-12-21T20:30:52ZengCopernicus PublicationsBiogeosciences1726-41701726-41892014-08-0111164459447610.5194/bg-11-4459-2014Methyl iodide production in the open oceanI. Stemmler0I. Hense1B. Quack2E. Maier-Reimer3Institute for Hydrobiology and Fisheries Science, University of Hamburg, CEN, Hamburg, GermanyInstitute for Hydrobiology and Fisheries Science, University of Hamburg, CEN, Hamburg, GermanyGeomar, Helmholtz Centre for Ocean Research, Kiel, GermanyMax Planck Institute for Meteorology, Hamburg, GermanyProduction pathways of the prominent volatile organic halogen compound methyl iodide (CH<sub>3</sub>I) are not fully understood. Based on observations, production of CH<sub>3</sub>I via photochemical degradation of organic material <i>or</i> via phytoplankton production has been proposed. Additional insights could not be gained from correlations between observed biological and environmental variables or from biogeochemical modeling to identify unambiguously the source of methyl iodide. In this study, we aim to address this question of source mechanisms with a three-dimensional global ocean general circulation model including biogeochemistry (MPIOM–HAMOCC (MPIOM – Max Planck Institute Ocean Model HAMOCC – HAMburg Ocean Carbon Cycle model)) by carrying out a series of sensitivity experiments. The simulated fields are compared with a newly available global data set. Simulated distribution patterns and emissions of CH<sub>3</sub>I differ largely for the two different production pathways. The evaluation of our model results with observations shows that, on the global scale, observed surface concentrations of CH<sub>3</sub>I can be best explained by the photochemical production pathway. Our results further emphasize that correlations between CH<sub>3</sub>I and abiotic or biotic factors do not necessarily provide meaningful insights concerning the source of origin. Overall, we find a net global annual CH<sub>3</sub>I air–sea flux that ranges between 70 and 260 Gg yr<sup>−1</sup>. On the global scale, the ocean acts as a net source of methyl iodide for the atmosphere, though in some regions in boreal winter, fluxes are of the opposite direction (from the atmosphere to the ocean).http://www.biogeosciences.net/11/4459/2014/bg-11-4459-2014.pdf |
| spellingShingle | I. Stemmler I. Hense B. Quack E. Maier-Reimer Methyl iodide production in the open ocean Biogeosciences |
| title | Methyl iodide production in the open ocean |
| title_full | Methyl iodide production in the open ocean |
| title_fullStr | Methyl iodide production in the open ocean |
| title_full_unstemmed | Methyl iodide production in the open ocean |
| title_short | Methyl iodide production in the open ocean |
| title_sort | methyl iodide production in the open ocean |
| url | http://www.biogeosciences.net/11/4459/2014/bg-11-4459-2014.pdf |
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