Junhua Yang1, Shichang Kang 1,3, Zhenming Ji2 1 State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Gansu 730000, China
2 School of Atmospheric Sciences, and Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Guangzhou 510275, China
3 CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China
Received:
May 29, 2017
Revised:
July 30, 2017
Accepted:
August 17, 2017
Download Citation:
||https://doi.org/10.4209/aaqr.2017.05.0156
Cite this article:
Yang, J., Kang, S. and Ji, Z. (2018). Sensitivity Analysis of Chemical Mechanisms in the WRF-Chem Model in Reconstructing Aerosol Concentrations and Optical Properties in the Tibetan Plateau. Aerosol Air Qual. Res. 18: 505-521. https://doi.org/10.4209/aaqr.2017.05.0156
HIGHLIGHTS
ABSTRACT
To investigate the effect of gas-phase chemical schemes and aerosol mechanisms on the reconstruction of the concentrations and optical properties of aerosols in the Tibetan Plateau (TP) and adjacent regions, two simulation experiments using the mesoscale Weather Research and Forecasting (WRF) meteorological model with the chemistry module (WRF-Chem) were performed in 2013. The RADM2 gas-phase chemical mechanism and the MADE/SORGAM aerosol scheme were selected in the first configuration, whereas the CBMZ gas and MOSAIC aerosol reaction schemes were included in the second simulation. The comparison demonstrated that chemical mechanisms play a key role in affecting the evolution of gas-phase precursors and aerosol processes. Specifically, compared with RADM2, CBMZ revealed lower O3 and higher NO2 surface concentrations, because of more efficient O3-NO titration, and higher HNO3 concentrations owing to more effective NO2 + OH reaction. SO2 could easily form particulate sulfate through cloud oxidation in RADM2. The MADE/SORGAM module presented higher surface PM2.5 and PM10 concentrations than did the MOSAIC module over the TP and in surrounding regions, because of the difference in aerosol compounds and the distribution of computed aerosol concentrations between modes and bins. The aerosol optical depth at 550 nm indicated a potential correlation with surface secondary inorganic aerosols concentrations. Higher surface sulfate and nitrate concentrations appeared to determine higher AOD values in MADE/SORGAM than in MOSAIC. Finally, the comparison with observations suggested that, the simulation performed using the CBMZ gas-phase chemical mechanism and MOSAIC aerosol module could be suitable for the efficient reconstruction of aerosols and their optical depth over the TP.
Keywords:
Chemical schemes; Aerosol concentration; Aerosol optical properties; Tibetan Plateau.
