The impact of different external sources of iron on the global carbon cycle
International audience Variable supply of iron to the ocean is often invoked to explain part of past changes in atmospheric CO2 (CO2atm). Using model simulations, we find that CO2atm is sensitive on the order of 15, 2, and 1 ppm to sedimentary, dust, and hydrothermal iron input. CO2atm is insensitiv...
Published in: | Geophysical Research Letters |
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Main Authors: | , , |
Other Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2014
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Subjects: | |
Online Access: | https://hal.archives-ouvertes.fr/hal-01128894 https://hal.archives-ouvertes.fr/hal-01128894/document https://hal.archives-ouvertes.fr/hal-01128894/file/2013GL059059.pdf https://doi.org/10.1002/2013GL059059 |
Summary: | International audience Variable supply of iron to the ocean is often invoked to explain part of past changes in atmospheric CO2 (CO2atm). Using model simulations, we find that CO2atm is sensitive on the order of 15, 2, and 1 ppm to sedimentary, dust, and hydrothermal iron input. CO2atm is insensitive to dust because it is not the major iron input to the Southern Ocean. Modifications to the relative export of Si(OH)4 to low latitudes are opposite to those predicted previously. Although hydrothermalism is the major control on the iron inventory in ~25% of the ocean, it remains restricted to the deep ocean, with minor effects on CO2atm. Nevertheless, uncertainties regarding the iron-binding ligand pool can have significant impacts on CO2atm. Ongoing expansion of iron observations as part of GEOTRACES will be invaluable in refining these results. |
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