Update on soil CO₂ flux monitoring at the illinois basin - Decatur Project, USA

The Illinois Basin - Decatur Project (IBDP) is a large-scale carbon capture and storage (CCS) project in Decatur, Illinois, USA demonstrating storage of one million metric tons of carbon dioxide (CO₂) in a deep saline reservoir. The IBDP Monitoring,Verification, and Accounting (MVA) program at the 0.65 km² study site includes a soil CO₂ flux monitoring network, measured weekly during the growing season since 2009 and a high-frequency flux and atmospheric C0₂ monitoring station. Over 11,000 flux measurements have been collected from the point network and over 50,000 flux measurements have been collected at a higher frequency from a LI-COR Biosciences® LI-8150 multiplexer. No anomalies related to CO₂ injection were identified. We also examined site-specific biophysical relationships among soil CO₂ flux, soil temperature, and soil moisture, and assessed the flux data to better characterize flux variability. This extensive dataset provides an opportunity to characterize site-wide flux variations in detail, and provides insights into ways that measured fluxes could be evaluated to identify atypical variations.