#A11 Soluble iron model development within the ACME

Abstract

An intermediate complexity soluble iron is currently being incorporated into the atmospheric part of the Accelerated Model for Climate and Energy (ACME) model in order to better understand the role of dust and combustion sources of iron to be processed in the atmosphere to become more soluble and impact ocean biogeochemistry.  Currently the ocean model include iron limitation and links between the iron and nitrogen cycle, and thus including a prognostic iron cycle is an important step in coupling the land to the ocean via the atmosphere. This model is more complicated than first generation models, and incorporates recent advances in atmospheric processing and differential source solubility, but allows soluble iron processing to occur without complicated chemistry or thermodynamic models. The overall scheme follows that of the previously implemented addition of soluble iron tracer to the bulk aerosol model.

To determine which modelling uncertainties dominate the potential supply of soluble iron to remote ocean regions, particularly those with a high nutrient low chlorophyll profile, a series of source attribution and atmospheric processing and deposition sensitivity studies are being undertaken. The dominant source of soluble iron to each ocean basin is defined, along with the sensitivity of that flux to modelled uncertainties in the atmospheric pH, chemical processing, and wet and dry deposition.