This dataset contains coupled reanalysis data for ocean biogeochemistry, generated through improved version of the NorCPM data assimilation system. The system assimilates monthly observations of sea surface temperature (SST) and temperature-salinity (TS) profiles using EnKF algorithm. The reanalysis utilized the medium-resolution Norwegian Earth System Model version 1 (NorESM1-ME), with biogeochemical (BGC) parameters optimized through EnKF data assimilation. The dataset spans globally and covers the timeframe from January 1, 1985, to December 31, 2022.