Mineralogy-based global anthropogenic combustion-iron emission inventory

• Main Author: Rathod, Sagar Dilipbhai
• Other Authors: Bond, Tami C
• Format: Thesis
• Language: English
• Published: 2021
• Subjects: iron; emissions; ocean; biogeochemistry; dust; industrial; Pacific; Southern Ocean
• Online Access: http://hdl.handle.net/2142/105958

Total and soluble iron modulate ocean biogeochemistry and global nitrogen and carbon cycle in over 40% of global ocean. The understanding of the current and future changes in oceanic productivity can be improved by understanding and constraining the atmospheric inputs of iron. Models generally agree with observations for total and soluble atmospheric iron concentrations over oceans except in the iron limited Southern Ocean where they underestimate by two to five orders of magnitudes. Anthropogenic combustion-iron emissions are thought to be the missing link in some of the ocean regions and are currently underestimated in inventories along with a poor fuel-based solubility representation approach in contrast to dust-iron emissions which are better constrained and have mineralogy-based solubility approach. Here we show that anthropogenic combustion-iron emissions can be about 1 Tg Fe/yr in the fine fraction, 10 times higher than all previous inventories. A large part of the difference is attributed to metal smelting which was not accounted for in previous inventories. Anthropogenic combustion-iron contributes 30-50% of the total and soluble iron to the iron limited North and Equatorial Pacific Ocean and less than 10% to the Southern Ocean. Modeled estimates agree with observations everywhere except in the Southern Ocean where the underestimation persists even with the realistic maximum anthropogenic emissions. For the first time, we represent anthropogenic combustion-iron as a function of its mineral components and transition from a fuel-specific solubility to a mineralogy-based solubility approach. We find that increasing complexity in representing anthropogenic combustion-iron solubility does not necessarily improve model-observation comparison. Limited Author requested closed access (OA after 2yrs) in Vireo ETD system