Iron Fertilization of the Southern Ocean: Regional Simulation and Analysis of C-Sequestration in the Ross Sea

• Main Author: Kevin Arrigo
• Language: unknown
• Published: 2016
• Subjects: 54 ENVIRONMENTAL SCIENCES; ANTARCTICA; CARBON; CARBONATES; DIATOMS; DRAWDOWN; ECOSYSTEMS; FERTILIZATION; IRON; NITRATES; NUTRIENTS; PHOSPHATES; PHYTOPLANKTON; PRODUCTION; SEAS; SIMULATION; Ross Sea; Southern Ocean; Antarc*; Antarctica
• Online Access: http://www.osti.gov/servlets/purl/1036239; https://www.osti.gov/biblio/1036239; https://doi.org/10.2172/1036239

A modified version of the dynamic 3-dimensional mesoscale Coupled Ice, Atmosphere, and Ocean model (CIAO) of the Ross Sea ecosystem has been used to simulate the impact of environmental perturbations upon primary production and biogenic CO2 uptake. The Ross Sea supports two taxonomically, and spatially distinct phytoplankton populations; the haptophyte Phaeocystis antarctica and diatoms. Nutrient utilization ratios predict that P. antarctica and diatoms will be driven to nitrate and phosphate limitation, respectively. Model and field data have confirmed that the Ross Sea is iron limited with only two-thirds of the macronutrients consumed by the phytoplankton by the end of the growing season. In this study, the CIAO model was improved to simulate a third macronutrient (phosphate), dissolved organic carbon, air-sea gas exchange, and the carbonate system. This enabled us to effectively model pCO2 and subsequently oceanic CO2 uptake via gas exchange, allowing investigations into the affect of alleviating iron limitation on both pCO2 and nutrient drawdown.