MICS-Asia II: The model intercomparison study for Asia Phase II methodology and overview of findings

Abstract Results from the Model Intercomparison Study Asia Phase II (MICS-Asia II) are presented. Nine different regional modeling groups simulated chemistry and transport of ozone (O 3 ), secondary aerosol, acid deposition, and associated precursors, using common emissions and boundary conditions derived from a global model. Four-month-long periods, representing 2 years and three seasons (i.e., March, July, and December in 2001, and March in 2002), are analyzed. New observational data, obtained under the EANET (the Acid Deposition Monitoring Network in East Asia) monitoring program, were made available for this study, and these data provide a regional database to compare with model simulations. The analysis focused around seven subject areas: O 3 and related precursors, aerosols, acid deposition, global inflow of pollutants and precursor to Asia, model sensitivities to aerosol parameterization, analysis of emission fields, and detailed analyses of individual models, each of which is presented in a companion paper in this issue of Atmospheric Environment . This overview discusses the major findings of the study, as well as information on common emissions, meteorological conditions, and observations.