Biogeochemical Equilibrium Responses to Maximal Productivity in High Nutrient Low Chlorophyll Regions

Abstract Whether ocean iron fertilization in high nutrient low chlorophyll (HNLC) regions is a practical geoengineering strategy to combat climate warming has been debated because the fate of absorbed carbon by remains unclear. We use an optimized oceanic biogeochemical inverse model explore equilibrium responses increased productivity major HNLC regions. find that overall downward shift nutrients and from surface intermediate deep waters with maximal Southern Ocean (SO), North Pacific (NP) eastern equatorial (EP). The efficiency soft tissue pump 37.8%, 2.7% 5.4% SO, EP NP simulation while atmospheric CO 2 concentration drawn down 45.1, 3.4 6.7 ppm, respectively. Meanwhile, global mean oxygen decreased 21.1%, 1.3% 2.4% simulation, accompanied expansion minimum zones 400%, 26% 63%, Our study indicates potential be effective approach mitigate but also strong impact on development hypoxia.