Aeolian iron mobilisation by dust-acid interactions and their implications for soluble iron deposition to the ocean: a test involving potential anthropogenic organic acidic species

作者：Luo Chao; Gao Yuan^*

来源：Environmental Chemistry, 2010, 7(2): 153-161.

DOI：10.1071/EN09116

Dust deposition is a major source of iron in certain oceanic regions. Many atmospheric processes, such as heterogeneous reactions with acidic species, may convert insoluble iron in dust to soluble forms that become bioavailable for phytoplankton uptake in the surface ocean. Here we report for the first time the effects of organic acidic species on iron dissolution using laboratory-measured conversion rates by oxalate, simulated in a global model to estimate soluble iron fluxes to the ocean. With the complexity and limited data from measurements relating to different sources for oxalate, we focus on the effect of oxalate of anthropogenic origin in this work as a first-step testing, and we apply a scaling factor for oxalate based on its relationship with aerosol sulfate observed by in situ measurements in the continental sites. The results show better correlation with the observations than the work including inorganic acids alone, suggesting the contribution of organic acids to Fe dissolution. However, the simulated iron solubility is lower than that derived from measurements, suggesting additional processes may contribute to Fe dissolution that should be included in the model. Total deposition of soluble iron to the global ocean including the effect by anthropogenic oxalate is similar to 0.34 Tg year(-1).

• 出版日期2010
• 单位rutgers