The CAFE model: A net production model for global ocean phytoplankton

The Carbon, Absorption, and Fluorescence Euphotic-resolving (CAFE) net primary production model is an adaptable framework for advancing global ocean productivity assessments by exploiting state-of-the-art satellite ocean color analyses and addressing key physiological and ecological attributes of phytoplankton. Here we present the first implementation of the CAFE model that incorporates inherent optical properties derived from ocean color measurements into a mechanistic and accurate model of phytoplankton growth rates (mu) and net phytoplankton production (NPP). The CAFE model calculates NPP as the product of energy absorption (Q(PAR)), and the efficiency (phi(mu)) by which absorbed energy is converted into carbon biomass (C-Phyto), while mu is calculated as NPP normalized to C-Phyto. The CAFE model performance is evaluated alongside 21 other NPP models against a spatially robust and globally representative set of direct NPP measurements. This analysis demonstrates that the CAFE model explains the greatest amount of variance and has the lowest model bias relative to other NPP models analyzed with this data set. Global oceanic NPP from the CAFE model (52 Pg C m(-2) yr(-1)) and mean division rates (0.34 day(-1)) are derived from climatological satellite data (2002-2014). This manuscript discusses and validates individual CAFE model parameters (e.g., Q(PAR) and phi(mu)), provides detailed sensitivity analyses, and compares the CAFE model results and parameterization to other widely cited models.