Fig. 5

Observations within and outside the NaOH plume. a. mean pCO\(_2\) (with standard deviation) for the pre- and post-trial observations, as well as observations collected in the immediate vicinity of the release, and at the near-field (NF), and downstream sampling locations. b. mean Alk (with standard deviation) as in panel a. c. the variation in surface ocean pH(ASV) mapped with a piloted vehicle during Day 2 of the experiment. We note there is an offset between the pH(ASV) and the pH observations shown in Figs. 3 and 4. The pH(ASV) is used here as a proxy to illustrate spatial changes, and not as an independent measurement of pH.