A metamodelling implementation of a two-way coupled mesoscale-microscale flow model for urban area simulations

Systems of coupled prognostic mesoscale and microscale models have been suggested as a tool to accurately simulate flows around artificial structures and over densely built urban areas. Implementations of such two-way coupling are burdened by scale mismatches as well as the formidable computational cost of online microscale calculations. A simplifying approach is proposed, where microscale feedbacks are spatially and temporally upscaled and assimilated into the mesoscale calculation. A two-way coupled model system is developed, consisting of the mesoscale model MEMO and the microscale model MIMO, employing interpolating metamodels. As an illustrative application, multi-day simulations for Athens, Greece are presented.