Zhou et al. (2025): High-resolution numerical assessment of large-scale riverine alkalinity modification scenarios along the southern coast of the United States

Xing Zhou, Annalisa Bracco, Takamitsu Ito and Chris Reinhard, IN: Preprint (cdrXiv), https://doi.org/10.70212/cdrxiv.2025408.v1

River-based alkalinity modifications represent potentially effective approaches for removing atmospheric CO₂ and mitigating anthropogenic climate change. Evaluating their effectiveness requires consideration of downstream impacts on coastal ocean CO₂ air–sea exchange following intervention. In this study, the authors applied a high-resolution (5 km) regional coupled physical and biogeochemical model (CROCO-PISCES) to assess two carbon dioxide removal approaches, alkalinity enhancement (AE) and enhanced weathering (EW), in the northern portion of the Gulf of Mexico. Alkalinity and dissolved inorganic carbon inputs were added to riverine outflow from the Mississippi and Atchafalaya Rivers according to eight hypothetical scenarios with variable magnitude and timing.

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