Multi-scale model surface layer

An extreme iron fertilization scenario modeled by Sarmiento and Orr (1991) relies on the sustained depletion of phosphorus in Southern Ocean surface waters by continuous iron addition. The three-dimensional, multi-layered model predicts a global increase of export production and the possibility of anoxia in deep oceanic waters. Specifically, the results indicate a POC export increase of 6-30 GtCy-1, i.e., a doubling of export production, after 100 years of fertilization. In addition, anoxia is predicted for certain parts of the southwest Indian Ocean. Considering the enormous scale of this hypothesized fertilization operation (0.6Mt utilizable Fey-1 Sarmiento Orr, 1991) and the low spatial resolution of the model, the exercise provides limited insights into more realistic iron fertilization scenarios. 

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