Description and evaluation of GMXe: a new aerosol submodel for global simulations (v1)

Abstract

We present a new aerosol microphysics and gas aerosol partitioning submodel (Global Modal-aerosol eXtension, GMXe) implemented within the ECHAM/MESSy Atmospheric Chemistry model (EMAC, version 1.8). The submodel is computationally efficient and is suitable for medium to long term simulations with global and regional models. The aerosol size distribution is treated using 7 log-normal modes and has the same microphysical core as the M7 submodel (Vignati et al., 2004). <br><br> The main developments in this work are: (i) the extension of the aerosol emission routines and the M7 microphysics, so that an increased (and variable) number of aerosol species can be treated (new species include sodium and chloride, and potentially magnesium, calcium, and potassium), (ii) the coupling of the aerosol microphysics to a choice of treatments of gas/aerosol partitioning to allow the treatment of semi-volatile aerosol, and, (iii) the implementation and evaluation of the developed submodel within the EMAC model of atmospheric chemistry. <br><br> Simulated concentrations of black carbon, particulate organic matter, dust, sea spray, sulfate and ammonium aerosol are shown to be in good agreement with observations (for all species at least 40% of modeled values are within a factor of 2 of the observations). The distribution of nitrate aerosol is compared to observations in both clean and polluted regions. Concentrations in polluted continental regions are simulated quite well, but there is a general tendency to overestimate nitrate, particularly in coastal regions (geometric mean of modelled values/geometric mean of observed data ≈2). In all regions considered more than 40% of nitrate concentrations are within a factor of two of the observations. Marine nitrate concentrations are well captured with 96% of modeled values within a factor of 2 of the observations

Earth System Chemistry integrated Modelling (ESCiMo) with the Modular Earth Submodel System (MESSy) version 2.51

“…To determine the physical and chemical properties of the atmospheric aerosol, the EMAC aerosol submodel GMXE (Pringle et al, 2010;Tost and Pringle, 2012) has been applied. GMXE calculates the microphysical properties of aerosols based on nucleation of sulfuric acid, condensation, and phase partitioning of semi-volatile inorganic components according to ISORROPIA-2 (Fountoukis and Nenes, 2007), coagulation, and a dynamical shift between the size categories on 4 log-normal modes.…”

Distributions and regional budgets of aerosols and their precursors simulated with the EMAC chemistry-climate model

“…Nowadays, a number of global aerosol models that can treat semi-volatile inorganic species that partition between the gas and aerosol phases exist (e.g. Adams et al, 1999;Adams and Seinfeld, 2002;Bauer and Koch, 2005;Myhre et al, 2006;Feng and Penner, 2007;Pringle et al, 2010a), but most models treat five main aerosol species: black carbon (BC), particulate organic matter (POM), sulfate aerosol (SO 2− 4 ), mineral dust (DU) and sea spray (SS) (see Textor et al, 2006, and reference therein). Zhang (2008, and references therin) clearly describes the history of the chemistry models, showing the large increase in our understanding of the processes involved in aerosol formations and interactions.…”

“…ammonia) especially for those for which the phase partitioning is temperature dependent (Pinder et al, 2004;De Meij et al, 2006). In this work, we take advantage of the stateof-the-art emissions inventory EDGAR-Climate Change and Impact Research (CIRCE), which provides emissions on a high spatial (0.1 × 0.1 • ) and temporal (monthly) resolution, together with a recently developed aerosol scheme implemented within the EMAC model (Pringle et al, 2010a).…”

ORACLE 2-D (v2.0): an efficient module to compute the volatility and oxygen content of organic aerosol with a global chemistry–climate model

“…ECHAM5 (Roeckner et al, 2006) serves as the atmospheric dynamic core that simulates atmospheric flow and is integrated in the base model layer of MESSy. The interface structure of MESSy links the base model with several atmospheric submodels that online simulate gas-phase chemistry (MECCA; Sander et al, 2011), inorganic aerosol microphysics and dynamics (GMXe; Pringle et al, 2010), organic aerosol formation and growth (ORACLE; Tsimpidi et al, 2014), emissions (ONLEM and OFFLEM; Kerkweg et al, 2006b), dry deposition and sedimentation (DRYDEP and SEDI; Kerkweg et al, 2006a), cloud scavenging (SCAV; Tost et al, 2006), cloud microphysics (CLOUD; Bacer et al, 2018), and aerosol optical properties (AEROPT; Lauer et al, 2007). EMAC has been extensively described and evaluated against ground-based and satellite observations (Pozzer et al, 2012;Tsimpidi et al, 2014Tsimpidi et al, , 2016Tsimpidi et al, , 2017Karydis et al, 2016Karydis et al, , 2017.…”