Optimal Resolution Urban Terrain Inputs to Microclimate Modeling for Local Climate Decision Support
As the effects of climate change become more evident in cities, the scientific community seeks deeper understanding of multi-scale interactions among the atmosphere, human systems and the overall earth system, making more explicit representation of urban terrain in weather and climate models necessary. Many studies have examined the differences in simulations of urban climate at various horizontal grid resolutions, but no studies have been performed that compare the results of running the models at the same horizontal grid resolution but with different resolutions of the urban terrain. We examine the differences in meteorological output from the Weather Research and Forecasting (WRF) model run at 270m horizontal resolution using 10m resolution urban terrain (morphology) inputs and 100m resolution inputs. We find that differences in urban terrain resolution may amplify or dampen the representation of shortwave absorption by low albedo concrete and asphalt and the re-radiation of this energy as heat to the neighbourhood, and we evaluate the relevance of these results to developing climate adaptation and mitigation strategies for cities at neighborhood scale.