10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Mineralogically-Speciated and Size-Resolved Global Combustion-Iron Emission Inventory
SAGAR RATHOD, Tami Bond, University of Illinois at Urbana Champaign
Abstract Number: 922 Working Group: Aerosols in Earth System
Abstract Global anthropogenic contribution of bioavailable iron to oceans is perturbing the ocean-atmosphere iron and carbon dioxide budget by enhancing phytoplankton growth (primary oceanic productivity) and carbon dioxide uptake. Quantification of iron, its speciation, and its representation in climate models is poorly understood due to the lack of size-resolved observations and mineral-speciation of iron at source and at oceans. This work presents a global size-resolved total and soluble iron emission inventory based on anthropogenic combustion activities. Iron fractions in particulate matter emitted from fuel-technology combinations were compiled and overlaid on a particulate matter emission inventory generated in SPEW (Speciated Particulate Emissions Wizard). The anthropogenic contribution of total iron for the year 2000 was 0.16(0.037-0.56) Tg/yr as PM1 and 0.20(0.040-1.5) Tg/yr as PM10.
The representation of iron in climate models for their transport and atmospheric processing requires speciated-iron emissions at source. Currently, combustion iron is modeled as a single mineral in the fine mode in CESM. Atmospheric processing is the low-pH iron mobilization in the minerals in particulate matter which enhances its solubility. This work presents speciated-iron emissions at source from combustion activities. Major iron-minerals were grouped into six classes: clays, oxyhydrides, sulfates, sulfides, carbonates, and metals and a temperature-dependent phase transformation model was applied on the initial iron speciation to estimate the iron speciation at different temperatures. Iron in the emission was grouped into clays, oxyhydrides, hematite, magnetite, sulfates, and carbonates which were then coupled with the total iron emissions and mineral-specific solubility. The results from this study will enable models represent and process combustion iron as a combination of different minerals and apply mineral-specific processing scheme.