Modeling the global ocean iron cycle

[1] We describe a model of the ocean transport and biogeochemical cycling of iron and the subsequent control on export production and macronutrient distributions. Ocean transport of phosphorus and iron are represented by a highly idealized six-box ocean model. Export production is parameterized simp...

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Bibliographic Details
Main Authors: Payal Parekh, Michael J. Follows, Edward Boyle
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.572.318
http://ocean.mit.edu/~mick/Papers/parekhetal2004.pdf
Description
Summary:[1] We describe a model of the ocean transport and biogeochemical cycling of iron and the subsequent control on export production and macronutrient distributions. Ocean transport of phosphorus and iron are represented by a highly idealized six-box ocean model. Export production is parameterized simply; it is limited by light, phosphate, and iron availability in the surface ocean. We prescribe the regional variations in aeolian deposition of iron and examine three parameterizations of iron cycling in the deep ocean: (1) net scavenging onto particles, the simplest model; (2) scavenging and desorption of iron to and from particles, analogous to thorium; and (3) complexation. Provided that some unknown parameter values can be set appropriately, all three biogeochemical models are capable of reproducing the broad features of the iron distribution observed in the modern ocean and explicitly lead to regions of elevated surface phosphate, particularly in the Southern Ocean. We compare the sensitivity of Southern Ocean surface macronutrient concentration to increased aeolian dust supply for each parameterization. Both scavenging-based representations respond to increasing dust supply with a drawdown of surface phosphate in an almost linear relationship. The complexation