A New Chemistry-Climate Model GRIMs-CCM: Model Evaluation of Interactive Chemistry-Meteorology Simulations

We describe a new chemistry-climate model, Global/Regional Integrated Model system Chemistry Climate Model (GRIMs-CCM), developed by coupling the chemistry modules of the GEOS-Chem chemical transport model to the GRIMs general circulation model. The GRIMs-CCM is driven by meteorological variables simulated by the GRIMs and uses simulated gas and aerosol concentrations to calculate the radiative transfer equations at each time step. The model is evaluated by comparing ozone and aerosol concentrations with respective observations from the surface networks and the satellite datasets. It is found that the GRIMs-CCM successfully reproduces the observed spatial distributions of annual-mean aerosol optical depth and captures the seasonal and latitudinal variations of total column ozone. The evaluation of simulated aerosols in surface air against the observations reveals that the model reproduces the observed temporal and spatial variations but shows biases in soil dust aerosols. We also estimate the climatic impact of aerosols by conducting two sets of 10-year simulations for the preindustrial and present conditions. The GRIMs-CCM shows the aerosol radiative forcing of - 0.30 W m(-2) from the preindustrial to present-day climates, comparable to the values from other climate model intercomparison projects. These results suggest that the GRIMs-CCM is suitable for studying chemistry-climate interactions and their changes over time.

Automated summary

This research introduces a new chemistry-climate model that combines a chemical transport model and a general circulation model to study the interactions and changes in chemistry and climate. The model is able to accurately reproduce the spatial distributions of aerosols and ozone, as well as simulate the temporal and spatial variations of aerosols, with some biases in soil dust aerosols.