Abstract

The depth at which organic carbon exported from the surface ocean is remineralised exerts a strong control over atmospheric composition. Recent work suggests that remineralisation depth is strongly correlated with temperature, however correlation does not imply causality. In this work we firstly show that the relationship between temperature and remineralisation depth is consistent with the fundamental relationships between temperature and respiration and temperature and viscosity, implying that the relationship may be causative. We then implement it in a numerical model of ocean carbon cycling and show that it leads to organic matter being mineralised too deep compared to reality. The implication of this is that environments not yet sampled such as blooms and upwelling regions in the Southern Ocean and around the Equator have much shallower mineralisation profiles than the open ocean low production biomes we have sampled to date. We will describe future observational programmes to test this hypothesis.