- The export of organic carbon from the surface ocean by sinking particles is an important, yet
highly uncertain, component of the global carbon cycle. Here we introduce a mechanistic assessment of the
global ocean carbon export using satellite observations, including determinations of net primary production
and the slope of the particle size spectrum, to drive a food-web model that estimates the production of sinking
zooplankton feces and algal aggregates comprising the sinking particle flux at the base of the euphotic
zone. The synthesis of observations and models reveals fundamentally different and ecologically consistent
regional-scale patterns in export and export efficiency not found in previous global carbon export assessments.
The model reproduces regional-scale particle export field observations and predicts a climatological mean
global carbon export from the euphotic zone of ~6 Pg C yr⁻¹. Global export estimates show small variation
(typically <10%) to factor of 2 changes in model parameter values. The model is also robust to the choices of
the satellite data products used and enables interannual changes to be quantified. The present synthesis of
observations and models provides a path for quantifying the ocean’s biological pump.