[A-CG41] Biogeochemical linkages between the ocean and the atmosphere during phytoplankton blooms

[ACG41-05] Impact of atmospheric iron inputs on marine primary productivity and nutrient cycling

*Kazuhiro Misumi¹, Daisuke Tsumune¹ (1.Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry)

Keywords:Iron, Nutrients, Numerical simulation

A micronutrient iron regulates marine primary productivity roughly one-third of the global ocean. Change in atmospheric iron deposition has been regarded as a factor controlling past climate changes through changing CO₂ uptake by the ocean. Current global-scale marine biogeochemical models are using different iron deposition products derived from various atmospheric transport models. The total amounts of bioavailable iron supplied to the ocean vary 1.4–32.7 Gmol yr^-1 among the models, being a large uncertainty to project future oceanic CO₂ uptake. The variation of the iron supply rates can be attributed to 1) difference in the total iron deposition rate, 2) treatment of atmospheric processing determining the solubility and 3) treatment of consecutive dissolution of iron from sinking particles in the ocean. In this talk, we will address impact of atmospheric iron inputs on marine primary productivity and nutrient cycles by reviewing previous studies and results from some idealized experiments.