Anthropogenic aerosols mask about one-third of the human-induced greenhouse warming, but the possible range of the aerosol climate forcing is large; it extends from -2 W m^-2 to close to zero. Reducing the uncertainty is crucial – in order to understand climate evolution in general, but also to know if forceful reductions in anthropogenic aerosol emissions will result in a boost of global warming or in a negligible climate effect. Estimates of anthropogenic aerosol climate effects inevitably rely to a large extent on Earth System Models (ESMs). It is a challenge for these models to accurately predict aerosol trends and their associated climate effects, in particular any effect related to clouds, as the underlying processes are complex, manifold, and extend over a large range of scales. We address this challenge by systematically exploring the relation between aerosols, clouds, and their effect on climate using the large-eddy simulation (LES) code MIMICA, developed in-house at the Department of Meteorology, Stockholm University (MISU). MIMICA is a local-area, three-dimensional, high-resolution atmospheric model that solves the anelastic, non-hydrostatic governing equations for momentum, potential temperature, and water vapor. It includes turbulence and surface-flux parameterizations, radiation, a two-moment cloud microphysical parameterization, and a two-moment aerosol microphysics module, providing a flexible framework for simulations of detailed aerosol-cloud processes. The code has previously been used extensively on HPC resources at NSC. The simulations will be initialized and evaluated against ground-based observations and satellite data. We will conduct simulations for three climatically relevant environments: the polar regions, the Amazon, and the polluted Po Valley in Italy.