Despite significant emissions of anthropogenic carbon dioxide (CO2) in cities, fluxes of CO2 to and from urban ecosystems can significantly impact the local carbon budget. In this work we used the city of Toronto as a testbed to compare two urban vegetation models: the Solar-induced chlorophyll fluorescence for Modelling Urban biogenic Fluxes (SMUrF) model and the Urban Vegetation Photosynthesis and Respiration Model (UrbanVPRM). We made several adjustments to both models to improve their agreement with estimates from three in-situ eddy-covariance flux towers in the region, improve the spatial resolution, and better represent biogenic fluxes in urban areas. While discrepancies remain between the updated models, likely due to the use of different driving data, these differences are significantly smaller than variations between anthropogenic CO2 estimated by global anthropogenic emission inventories. We find that during summer afternoons both the UrbanVPRM and SMUrF models predict significant uptake of CO2, representing between half and all of Toronto's anthropogenic summer afternoon emissions, depending on the anthropogenic emissions inventory used. This illustrates the significant impact of urban biogenic CO2 fluxes.
Modification and Comparison of two urban vegetation models in Toronto, Canada
Host: Eylon Vakrat