A Phytoplankton Class-Specific Marine Primary Productivity Model Using MODIS Data

Abstract

The phytoplankton pigment absorption $(a_{{\rm{ph}}})$ -based productivity model (AbPM) is commonly used to estimate marine net primary production (NPP). In the AbPM, $a_{{\rm{ph}}}$ is used as the key predictor of phytoplankton photosynthetic efficiency. Previous studies have shown that the size of phytoplankton could affect the photosynthetic efficiency. Thus, a size-fractionated AbPM was proposed by considering how phytoplankton size influenced the global quantum yield of phytoplankton photosynthesis. The sea surface temperature (SST) was also used to further improve AbPM performance in cold waters (SST in situ NPP data, which were collected from different marine monitoring sites. Compared with the original AbPM, the new model not only had an excellent performance at each marine monitoring site, but also had an improved accuracy over the Southern Ocean. Although additional studies need to be conducted for confirmation, this size-fractionated model could be a reasonable and accurate method for the estimation of global ocean NPP.