Data supporting the study: High-frequency in situ total alkalinity measurements for monitoring ocean alkalinity enhancement field trials

These data originate from an integrated sensor package deployed within ~60 m of an outfall used for alkaline feedstock addition during Ocean Alkalinity Enhancement (OAE) field trials conducted in Halifax Harbour, Canada, in 2023 and 2024. The deployment included an autonomous Lab-on-a-Chip (LoC) total alkalinity (TA) analyzer together with sensors measuring pCO₂, pH, salinity, temperature, and turbidity. The dataset provides high-frequency measurements used to examine carbon system variability and changes in TA associated with OAE dosing during the field trials.Further methodological details and analysis are described in:<br>Zabihihesari et al., <i>High-frequency in situ total alkalinity measurements for monitoring ocean alkalinity enhancement field trials</i>, <b>Communications Engineering</b>, 2026. https://doi.org/10.1038/s44172-026-00665-w