The origin of water soluble particulate iron in the Asian atmospheric outflow

Abstract

Iron, and in particular water soluble iron, is an important trace nutrient in the surface ocean, and therefore an important component in the global carbon cycle. Deposition of Asian aerosol is thought to be a primary source of water soluble iron in the northern Pacific. Analysis of aerosol samples obtained during the Aerosol Characterization Experiment (ACE)–Asia field campaign from Jeju Island, Korea, which intercepts the outflow from the Asian continent, shows that water soluble iron is not dominated by mineral dust sources even during large dust storms. Instead, our analysis indicates that particulate soluble iron and elemental carbon concentrations are correlated. This leads to the conclusion that soluble iron in this region is strongly connected to anthropogenic activity and not connected to mineral dust emissions, especially if the budget averaged over annual time scales is considered.