MADE-in: A new aerosol microphysics submodel for global simulation of insoluble particles and their mixing state

Abstract

Black carbon (BC) and mineral dust are among the most abundant insolubleaerosol components in the atmosphere. When released, most BC and dustparticles are externally mixed with other aerosol species. Throughcoagulation with particles containing soluble material and condensation ofgases, the externally mixed particles may obtain a liquid coating and betransferred into an internal mixture. The mixing state of BC and dust aerosolparticles influences their radiative and hygroscopic properties, as well astheir ability of forming ice crystals. We introduce the new aerosol microphysics submodel MADE-in, implementedwithin the ECHAM/MESSy Atmospheric Chemistry global model (EMAC). MADE-in isable to track mass and number concentrations of BC and dust particles intheir different mixing states, as well as particles free of BC and dust.MADE-in describes these three classes of particles through a superposition ofseven log-normally distributed modes, and predicts the evolution of theirsize distribution and chemical composition. Six out of the seven modes aremutually interacting, allowing for the transfer of mass and number among them.Separate modes for the different mixing states of BC and dust particles inEMAC/MADE-in allow for explicit simulations of the relevant aging processes,i.e. condensation, coagulation and cloud processing. EMAC/MADE-in has beenevaluated with surface and airborne measurements and mostly performs wellboth in the planetary boundary layer and in the upper troposphere andlowermost stratosphere. © 2011 Author(s).