Impact of physical and biological processes on temporal variations of the ocean carbon sink in the mid-latitude North Atlantic (2002-2016)

•Annual mean seawater pCO2 has not increased between 2002 and 2016 at the PAP site.•The winter-summer seasonality of seawater pCO2 has however increased with time.•The study area was a carbon sink with increasing CO2 flux into the ocean.•Redfieldian carbon consumption was observed during the spring blooms.•Gas exchange, biological production and mixing explain most of the pCO2 variability.