Myers Stewart et al. (2025): Assessing the limitations of commercial sensors and models for supporting marine carbon dioxide removal (mCDR) monitoring: a case study
Tristen Myers Stewart, Peter Regier, Kyle Hinson, Carolina Torrez Sanchez, Quinn Mackay, Nicholas David Ward and Jessica Cross, IN: Frontiers in Climate, https://doi.org/10.3389/fclim.2025.1649723
Several unknowns remain surrounding marine Carbon Dioxide Removal (mCDR) monitoring, reporting, and verification (MRV) practices and capabilities. Current in-situ sensor technology is limited (primarily pH and pCOâ‚‚), requiring calculations and assumptions to estimate changes in carbonate chemistry parameters, including total alkalinity (TA). Considering that cost, energy consumption, and accuracy of commercial sensors can vary by orders of magnitude, understanding how well existing sensors perform in an mCDR context is important for this emerging community. Likewise, documenting sensor limitations and how relatively simple models can optimize sensor deployments will improve MRV efforts and support protocol development. Here the authors 1) compare performance of a variety of commercially available sensors in a blind mesocosm experiment simulating ocean alkalinity enhancement (OAE), and how sensor performance impacted carbonate chemistry estimates; 2) evaluate if sensors distinguish the OAE signal from natural variability during a small-scale OAE field test in Sequim Bay, WA, USA, and 3) use an idealized ocean biogeochemistry model to explore optimal sensor network design based on (1) and (2).