Ocean Science Toward a multivariate reanalysis of the North Atlantic Ocean biogeochemistry during 1998–2006 based on the assimilation of

Abstract. Today, the routine assimilation of satellite data into operational models of ocean circulation is mature enough to enable the production of global reanalyses de-scribing the ocean circulation variability during the past decades. The expansion of the “reanalysis ” concept from ocean physics to biogeochemistry is a timely challenge that motivates the present study. The objective of this pa-per is to investigate the potential benefits of assimilating satellite-estimated chlorophyll data into a basin-scale three-dimensional coupled physical–biogeochemical model of the North Atlantic. The aim is on the one hand to improve fore-casts of ocean biogeochemical properties and on the other hand to define a methodology for producing data-driven cli-matologies based on coupled physical–biogeochemical mod-eling. A simplified variant of the Kalman filter is used t