MICS Asia Phase II—Sensitivity to the aerosol module

Abstract

In the framework of the model inter-comparison study -Asia Phase II (MICS2), where eight models are compared over East Asia, this paper studies the influence of different parameterizations used in the aerosol module on the aerosol concentrations of sulfate and nitrate in PM 10 .An intracomparison of aerosol concentrations is done for March 2001 using different configurations of the aerosol module of one of the model used for the intercomparison. Single modifications of a reference setup for model configurations are performed and compared to a reference case. These modifications concern the size distribution, i.e. the number of sections, and physical processes, i.e. coagulation, condensation/evaporation, cloud chemistry, heterogeneous reactions and sea-salt emissions.Comparing monthly averaged concentrations at different stations, the importance of each parameterization is first assessed. It is found that sulfate concentrations are little sensitive to sea-salt emissions and to whether condensation is computed dynamically or by assuming thermodynamic equilibrium. Nitrate concentrations are little sensitive to cloud chemistry. However, a very high sensitivity to heterogeneous reactions is observed.Thereafter, the variability of the aerosol concentrations to the use of different chemistry transport models (CTMs) and the variability to the use of different parameterizations in the aerosol module are compared. For sulfate, the variability to the use of different parameterizations in the aerosol module is lower than the variability to the use of different CTMs. However, for nitrate, for monthly averaged concentrations averaged over four stations, these two variabilities have the same order of magnitude.

Application of WRF/Chem-MADRID and WRF/Polyphemus in Europe – Part 1: Model description, evaluation of meteorological predictions, and aerosol–meteorology interactions

“…A detailed model description setup of Polair3d/Polyphemus is given by Sartelet et al (2007). Compared with the study of Sartelet et al (2007), major updates in the model treatments include the gas-phase chemistry, the calculation of photolysis rates, the treatment of organic aerosols, the number of vertical levels and the land use cover.…”

“…WRF/Chem-MADRID has been applied to eastern Texas in the US to simulate PM and its interactions with meteorology with different gas/particle mass transfer approaches (Zhang et al, 2010a), to the eastern US to forecast realtime air quality (Chuang et al, 2011), and to the continental US (CONUS) to simulate surface O 3 and PM concentrations and aerosol feedbacks using different gas-phase mechanisms and different aerosol modules . The air quality modeling platform Polyphemus with the CTM Polair3D has been widely used for modeling pollution buildup and transport on urban to continental scales (e.g., Sartelet et al, 2008Sartelet et al, , 2012Royer et al, 2011), and specifically to simulate the year 2001 over Europe . A detailed model description setup of Polair3d/Polyphemus is given by Sartelet et al (2007).…”

“…The air quality modeling platform Polyphemus with the CTM Polair3D has been widely used for modeling pollution buildup and transport on urban to continental scales (e.g., Sartelet et al, 2008Sartelet et al, , 2012Royer et al, 2011), and specifically to simulate the year 2001 over Europe . A detailed model description setup of Polair3d/Polyphemus is given by Sartelet et al (2007). Compared with the study of Sartelet et al (2007), major updates in the model treatments include the gas-phase chemistry, the calculation of photolysis rates, the treatment of organic aerosols, the number of vertical levels and the land use cover.…”

Modeling of photolysis rates over Europe: impact on chemical gaseous species and aerosols

“…The ChemistryTransport Model (CTM) Polair3D of Polyphemus has been used for many applications: e.g. sensitivity analysis of ozone (Mallet, 2005), of particulate matter (Sartelet et al, 2008;Roustan et al, 2010), modelling of mercury and heavy metal at continental scale (Roustan and Bocquet, 2006) with respect to 3 European databases (European Monitoring and Evaluation Programme (EMEP), BDQA and AirBase). For gaseous chemistry, the chemical mechanism used in the model is the Regional Atmospheric Chemistry Mechanism (RACM) (Stockwell et al, 1997) (82 gas species).…”

Modeling air pollution in Lebanon: evaluation at a suburban site in Beirut during summer

“…WRF has been evaluated against observations in many regions (Borge et al, 2008;Carvalho et al, 2012;Molders, 2008) but, to our knowledge, has never been applied to Lebanon. The Polyphemus/Polair3D CTM has been evaluated over Europe Couvidat et al, 2012), Asia (Sartelet et al, 2008), and North America , but not in the Middle East region. This study aims to investigate air pollution in Beirut in July 2011 via meteorological and air quality modeling.…”