Underway pH of seawater sampled during CCGS John P. Tully cruises in the northeast Pacific Ocean from Vancouver Island to Station P from 2019 to 2020

The pH (in situ, total scale) of near surface seawater was measured from the CCGS John P. Tully while underway during three Canadian Line P cruises conducted from 2019 through 2020. A prototype instrument, BGC-SUMO (Y. Takeshita, MBARI), was plumbed into the ship's seawater intake line to measure near surface pH while a collocated thermosalinograph measured near surface salinity and temperature from the same flow stream. This dataset provides information on these properties.