GRIMs-Chem Two-Way Chemistry-Climate Coupled Model System with Aerosol Feedback in East Asia

We investigate the effects of aerosols on regional climate over East Asia using chemistry-climate coupled model system (GRIMs-Chem), which is developed by coupling the Global/Regional Integrated Model system (GRIMs) with an online aerosol module from GEOS-Chem, a global 3D chemical transport model. The GRIMs-Chem includes sulfate, nitrate, ammonium, organic carbon, black carbon, sea salt, and soil dust aerosols. In this study, we conduct two long-term aerosol simulations with and without interactive aerosol effects in the GRIMs-Chem model to investigate the interactions of aerosols and regional climate in East Asia. We first evaluate the simulated aerosol concentrations by comparing with surface observations from ground- and satellite-based aerosol concentrations. The comparison shows that the GRIMs-Chem well reproduces the observed spatiotemporal variation of aerosols. We then investigate the effects of anthropogenic aerosols on regional climate by comparing the two simulation results. We find that the meteorological variability, such as monsoon and El Niño, affects regional aerosol concentrations and that aerosols affect the weather again through the feedback processes with aerosol direct and indirect effects.