A compiled data product of underway pCO2 measurements from 77 individual cruise datasets collected from NOAA Ship Ka'imimoana in the Equatorial Pacific from 1996 through 2010 (NCEI Accession 0276699)

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 the NOAA Ka'imimoana from 1996 through 2010 as a companion project to the biannual servicing of the Tropical Atmosphere Ocean (TAO) Array moorings. The cruises during the 15-year period included 77 transects of the equatorial Pacific between 95°W and 165°E, and spanned several El Niño events.