Carbon Cycle Dynamics on the Atlantic Continental Margin


OCCI Funded Project: 2009

One important yet unknown question in the carbon cycle research is what are the feedbacks between net community production (NCP) – a measure of the net amount of carbon removed from the atmosphere – and gross primary production (GPP) – the total amount of carbon fixed by photosynthetic organisms? The Atlantic continental margin is an ideal natural laboratory for exploring the question of these feedbacks because satellite chlorophyll data suggest there will be large zonal gradients in NCP and GPP as one crosses from the coastal zone to the open ocean (Fig. 1). I will use novel gas tracers, namely oxygen/argon ratios and triple oxygen isotopes, to quantify NCP and GPP on three contrasting transects across the Atlantic continental margin, in order to provide (i) the first quantification of GPP – the base of the biological carbon cycle – from in situ methods on the Atlantic continental margin, and (ii) an investigation of the feedbacks between NCP and GPP, which should lead to better predictive power of how NCP will change as climate changes.