A compiled data product of underway pCO2 measurements from 63 individual cruise data sets collected on board Ships of Opportunity (SOOP) transiting the Pacific Ocean, from March 2004 through October 2018 (NCEI Accession 0280595)

As part of a multi-year effort to quantify the flux of CO2 between the ocean and atmosphere, the Ocean Climate Observation Program of the National Oceanic and Atmospheric Administration (NOAA) supports the deployment of underway CO2 systems on NOAA research ships and volunteer observing ships (VOS) in the Atlantic and Pacific Oceans. The CO2 group of NOAA's Pacific Marine Environmental Laboratory (PMEL) has been monitoring sea surface CO2 concentrations in the equatorial Pacific since 1982. This is a particularly dynamic area exhibiting significant variation of CO2 concentrations, both interannually due to the effect of periodic El Niño events, and seasonally due to the changes in wind strength and upwelling patterns. By measuring the pCO2 in both the sea surface and atmosphere, along with sea surface temperature, pressure, and wind speed, the flux of CO2 can be calculated, affording a broader understanding of key processes and changes in these processes in the ocean on decadal time scales. A strong upwelled-driven inverse pCO2-SST relationship exists across the equatorial Pacific, allowing the development of an empirical approach to obtain highly resolved pCO2 distributions and CO2 fluxes. This data package represents pCO2 gathered by PMEL onboard VOS container ships from 2004 through 2018. The cruises during the 15-year period included 63 transects of the Pacific Ocean between the North Pacific West Coast and New Zealand/Australia.