Early steps towards modelling the phytoplankton-heat feedback

Introduction Phytoplankton in order to survive in the upper ocean carry out photosynthesis absorbing the solar radiation penetrating in the ocean. Thereby they also absorb heat. High biomass during the spring bloom is thought to substantially affect the penetration of light and in turn heat in the upper ocean. The biological effect of this process has been extensively investigated and is described as the Self Shading effect. However the possible physical effects on the thermal structure and therefore on stratification of the water column are still poorly understood. Here we study the impact of marine biomass on ocean stratification and sea surface temperature (SST) using an Ocean General Circulation Model (OPA; Madec and Imbard, 1996; Madec et al., 1999) coupled to a Dynamic Green Ocean Model (Buitenhuis et al., this meeting; Aumont et al., 2003). Results