The role of external inputs and internal cycling in shaping the global ocean cobalt distribution : insights from the first cobalt biogeochemical model
Hawco, Nicholas J.
Bundy, Randelle M.
Landing, William M.
Morton, Peter L.
Saito, Mak A.
MetadataShow full item record
Cobalt is an important micronutrient for ocean microbes as it is present in vitamin B12 and is a co‐factor in various metalloenzymes that catalyze cellular processes. Moreover, when seawater availability of cobalt is compared to biological demands, cobalt emerges as being depleted in seawater, pointing to a potentially important limiting role. To properly account for the potential biological role for cobalt, there is therefore a need to understand the processes driving the biogeochemical cycling of cobalt and, in particular, the balance between external inputs and internal cycling. To do so, we developed the first cobalt model within a state‐of‐the‐art three‐dimensional global ocean biogeochemical model. Overall, our model does a good job in reproducing measurements with a correlation coefficient of >0.7 in the surface and >0.5 at depth. We find that continental margins are the dominant source of cobalt, with a crucial role played by supply under low bottom‐water oxygen conditions. The basin‐scale distribution of cobalt supplied from margins is facilitated by the activity of manganese‐oxidizing bacteria being suppressed under low oxygen and low temperatures, which extends the residence time of cobalt. Overall, we find a residence time of 7 and 250 years in the upper 250 m and global ocean, respectively. Importantly, we find that the dominant internal resupply process switches from regeneration and recycling of particulate cobalt to dissolution of scavenged cobalt between the upper ocean and the ocean interior. Our model highlights key regions of the ocean where biological activity may be most sensitive to cobalt availability.
© The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Global Biogeochemical Cycles 32 (2018): 594-616, doi:10.1002/2017GB005830.
Suggested CitationGlobal Biogeochemical Cycles 32 (2018): 594-616
The following license files are associated with this item:
Showing items related by title, author, creator and subject.
Cobalt and nickel in the Peru upwelling region : a major flux of labile cobalt utilized as a micronutrient Saito, Mak A.; Moffett, James W.; DiTullio, Giacomo R. (American Geophysical Union, 2004-12-28)The geochemistry of cobalt in the Peru upwelling region is dominated by its importance as a micronutrient. A large and previously undocumented flux of labile cobalt behaved as a micronutrient with correlations with major ...
Cobalt, manganese, and iron near the Hawaiian Islands : a potential concentrating mechanism for cobalt within a cyclonic eddy and implications for the hybrid-type trace metals Noble, Abigail E.; Saito, Mak A.; Maiti, Kanchan; Benitez-Nelson, Claudia R. (2007-09-26)The vertical distributions of cobalt, iron, and manganese in the water column were studied during the E-Flux Program (E-Flux II and III), which focused on the biogeochemistry of cold-core cyclonic eddies that form in the ...
Dissolved Cobalt and Labile Cobalt from Leg 2 (Hilo, HI to Papeete, French Polynesia) of the US GEOTRACES Pacific Meridional Transect (PMT) cruise (GP15, RR1815) on R/V Roger Revelle from October to November 2018 Saito, Mak A. (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: email@example.com, 2020-07-24)Dissolved Cobalt and Labile Cobalt from Leg 2 (Hilo, HI to Papeete, French Polynesia) of the US GEOTRACES Pacific Meridional Transect (PMT) cruise (GP15, RR1815) on R/V Roger Revelle from October to November 2018. For a ...