Evaluation of global EMEP MSC-W (rv4.34) WRF (v3.9.1.1) model surface concentrations and wet deposition of reactive N and S with measurements

Abstract. Atmospheric pollution has many profound effects on human health, ecosystems, and the climate. Of concern are high concentrations deposition of reactive nitrogen (Nr) species, especially reduced N (gaseous NH3, particulate NH4+). chemistry transport models (ACTMs) crucial to understanding sources impacts Nr its potential mitigation. Here we undertake first evaluation global version EMEP MSC-W ACTM driven by WRF meteorology (1∘×1∘ resolution), with a focus surface wet S species relevant investigation atmospheric secondary inorganic aerosol (SIA). The model–measurement comparison is conducted both spatially temporally, covering 10 monitoring networks worldwide. Model simulations for 2010 compared use HTAP ECLIPSEE (ECLIPSE annual total EDGAR monthly profile) emissions inventories; those 2015 used only. Simulations primary pollutants somewhat sensitive choice inventory in places where regional differences between two inventories apparent (e.g. China) but much less components. For example, difference modelled mean NH3 concentration using 18 % (HTAP: 0.26 µg m−3; ECLIPSEE: 0.31 m−3) only 3.5 NH4+ 0.316 0.305 m−3). Comparisons model measurements demonstrate that captures overall spatial seasonal variations well major NO2, SO2, HNO3, NH4+, NO3-, SO42- their East Asia, Southeast Europe, North America. shows better correlations average Asia (mean R seven species: R7‾=0.73), Europe (R7‾=0.67), America (R7‾=0.63) than (R5‾=0.35) (data 2015), which suggests issues latter network. Temporally, agree higher spring summer lower winter. slightly underestimates precipitation (by 13 %–45 %) agrees all four world regions (0.65–0.94 range). High measured also observed except Asia. N, greatest consistency (0.75–0.82 range), followed (R=0.68) (R=0.61). Model–measurement bias varies different networks; NO3- largest smallest greater uniformity biases driver discrepancies (aside from differing representativeness uncertainties measurements) shortcomings absolute rather modelling processes. comprehensive evaluations presented this study support application framework analysis current future budgets SIA.