PNNL

Abstract

We introduce MADE3 (Modal Aerosol Dynamics for Europe, adapted for global applications, version 3), an aerosol dynamics submodel for application in a global chemistry general circulation model, that builds on the predecessor aerosol submodels MADE and MADE-in. The main new features of MADE3 are the explicit representation of coarse particle interactions with fine particles and gases, and the inclusion of the hydrochloric acid (HCl)/chloride (Cl??) partitioning between the gas and condensed phases. The aerosol size distribution is represented in the new model as a superposition of nine lognormal modes: one for fully soluble particles, one for insoluble particles, and one for mixed particles in each of three size ranges (Aitken, accumulation, and coarse mode size ranges). In order to assess MADE3’s performance we compare it to its predecessor MADE and to the much more detailed particle-resolved aerosol model PartMC-MOSAIC in a box model application. MADE3 and MADE results are very similar, except when the aerosol is dominated by sea spray particles. In such cases, Cl?? concentrations are lower in MADE3 than in MADE due to the HCl/Cl?? partitioning. Additionally, the aerosol nitrate concentration is higher in MADE3 due to the uptake on coarse particles. MADE3 and PartMCMOSAIC show substantial differences in the fine particle size distributions (sizes . 2µm) that could be relevant when simulating climate effects on a global scale. Nevertheless, the agreement between MADE3 and PartMC-MOSAIC is very good when it comes to coarse particle size distribution, and also in terms of aerosol composition. Considering these results and the well-established ability of MADE in reproducing observed aerosol loadings and composition, MADE3 seems suitable for application within a global model.