Biogenic Fluxes of Carbon Dioxide in and Around the Greater Toronto and Hamilton Area

Fluxes of carbon dioxide (CO) to and from vegetation can be significant on a regional scale. It is therefore important to understand biogenic CO fluxes in order to quantify local carbon budgets. However, these fluxes are often difficult to estimate in urban emission studies. This work uses the Solar Induced Fluorescence (SIF) for Modelling Urban biogenic Fluxes (SMUrF) model and the Urban Vegetation Photosynthesis and Respiration Model (UrbanVPRM) to estimate biogenic CO fluxes in and around the Greater Toronto and Hamilton Area, the most populous region in Canada. We have made several modifications to both vegetation models to improve the agreement with eddy-covariance flux towers in the region and improve estimates over urban areas. In our presentation, we will describe these improvements and our application of these modified models. In particular, we investigate biogenic CO fluxes in the Greenbelt of Ontario; a region surrounding the Greater Toronto and Hamilton Area designed to protect the region’s croplands and natural landscape from urban sprawl. We find that this region absorbs significant amounts of CO annually and the recently proposed changes to the Greenbelt will result in reduced sequestration by the Greenbelt. We also investigate the amount of CO absorbed by vegetation estimated by SMUrF and UrbanVPRM in the city of Toronto, Canada. Lastly, we compare the results from this study to anthropogenic COemission inventories. This work will help constrain biogenic fluxes for use in urban emission studies and may help to inform policy makers and city planners on how vegetation in and around the city affects CO concentrations, and thus carbon budgets.