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Towards accounting for dissolved iron speciation in global ocean models
- Source :
- EPIC3Biogeosciences, COPERNICUS GESELLSCHAFT MBH, 8(10), pp. 3025-3039, ISSN: 1726-4170, Biogeosciences, Biogeosciences, Vol 8, Iss 10, Pp 3025-3039 (2011), Biogeosciences, 2011, 8 (10), pp.3025-3039. ⟨10.5194/bg-8-3025-2011⟩, Biogeosciences, European Geosciences Union, 2011, 8 (10), pp.3025-3039. ⟨10.5194/bg-8-3025-2011⟩, Biogeosciences (BG), 8 (10). pp. 3025-3039.
- Publication Year :
- 2011
- Publisher :
- COPERNICUS GESELLSCHAFT MBH, 2011.
-
Abstract
- The trace metal iron (Fe) is now routinely included in state-of-the-art ocean general circulation and biogeochemistry models (OGCBMs) because of its key role as a limiting nutrient in regions of the world ocean important for carbon cycling and air-sea CO2 exchange. However, the complexities of the seawater Fe cycle, which impact its speciation and bioavailability, are simplified in such OGCBMs due to gaps in understanding and to avoid high computational costs. In a similar fashion to inorganic carbon speciation, we outline a means by which the complex speciation of Fe can be included in global OGCBMs in a reasonably cost-effective manner. We construct an Fe speciation model based on hypothesised relationships between rate constants and environmental variables (temperature, light, oxygen, pH, salinity) and assumptions regarding the binding strengths of Fe complexing organic ligands and test hypotheses regarding their distributions. As a result, we find that the global distribution of different Fe species is tightly controlled by spatio-temporal environmental variability and the distribution of Fe binding ligands. Impacts on bioavailable Fe are highly sensitive to assumptions regarding which Fe species are bioavailable and how those species vary in space and time. When forced by representations of future ocean circulation and climate we find large changes to the speciation of Fe governed by pH mediated changes to redox kinetics. We speculate that these changes may exert selective pressure on phytoplankton Fe uptake strategies in the future ocean. In future work, more information on the sources and sinks of ocean Fe ligands, their bioavailability, the cycling of colloidal Fe species and kinetics of Fe-surface coordination reactions would be invaluable. We hope our modeling approach can provide a means by which new observations of Fe speciation can be tested against hypotheses of the processes present in governing the ocean Fe cycle in an integrated sense
- Subjects :
- 0106 biological sciences
010504 meteorology & atmospheric sciences
lcsh:Life
010501 environmental sciences
01 natural sciences
Carbon cycle
Total inorganic carbon
lcsh:QH540-549.5
Genetic algorithm
Phytoplankton
Trace metal
14. Life underwater
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment
Ecology, Evolution, Behavior and Systematics
Earth-Surface Processes
0105 earth and related environmental sciences
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere
Chemistry
010604 marine biology & hydrobiology
Ocean current
lcsh:QE1-996.5
Biogeochemistry
lcsh:Geology
lcsh:QH501-531
13. Climate action
Environmental chemistry
Seawater
lcsh:Ecology
Subjects
Details
- ISSN :
- 17264170 and 17264189
- Database :
- OpenAIRE
- Journal :
- EPIC3Biogeosciences, COPERNICUS GESELLSCHAFT MBH, 8(10), pp. 3025-3039, ISSN: 1726-4170, Biogeosciences, Biogeosciences, Vol 8, Iss 10, Pp 3025-3039 (2011), Biogeosciences, 2011, 8 (10), pp.3025-3039. ⟨10.5194/bg-8-3025-2011⟩, Biogeosciences, European Geosciences Union, 2011, 8 (10), pp.3025-3039. ⟨10.5194/bg-8-3025-2011⟩, Biogeosciences (BG), 8 (10). pp. 3025-3039.
- Accession number :
- edsair.doi.dedup.....055f3ba1122607c7a0c3395e97394448