We assembled a dataset of 14C-based productivity measurements to understand the critical variables required for accurate assessment of daily depth-integrated phytoplankton carbon fixation (PP(PPeu)u) from measurements of sea surface pigment concentrations (Csat)(Csat). From this dataset, we developed a light-dependent, depth-resolved model for carbon fixation (VGPM) that partitions environmental factors affecting primary production into those that influence the relative vertical distribution of primary production (Pz)z) and those that control the optimal assimilation efficiency of the productivity profile (P(PBopt). The VGPM accounted for 79% of the observed variability in Pz and 86% of the variability in PPeu by using measured values of PBopt. Our results indicate that the accuracy of productivity algorithms in estimating PPeu is dependent primarily upon the ability to accurately represent variability in Pbopt. We developed a temperature-dependent Pbopt model that was used in conjunction with monthly climatological images of Csat sea surface temperature, and cloud-corrected estimates of surface irradiance to calculate a global annual phytoplankton carbon fixation (PPannu) rate of 43.5 Pg C yr‒1. The geographical distribution of PPannu was distinctly different than results from previous models. Our results illustrate the importance of focusing Pbopt model development on temporal and spatial, rather than the vertical, variability.

The Continuous Plankton Recorder (CPR) Survey is the most geographically extensive marine monitoring programme in the world. Today the Survey is operated by the Marine Biological Association, based in Plymouth, UK. Operating since 1931, the Continuous Plankton Recorder (CPR) survey is recognised as the longest sustained and geographically most extensive marine biological survey in the world. The dataset comprises a uniquely large record of marine biodiversity covering ~800 taxa over multi-decadal periods. In terms of our scientific understanding of natural variability and human-induced change on our oceans, the CPR survey is of global importance and it is used by scientists, policy makers and environmental managers across the world. The data is used to examine strategically important science pillars such as climate change, human health, fisheries, biodiversity, pathogens, invasive species, ocean acidification and natural capital. The results have included the globally first documented studies of large-scale ecological regime shifts, and of biogeographic, phenological and trans-arctic migrations in the marine environment in response to climate change. The data in this sampling event resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 252,385 records. 2 extension data tables also exist. An extension record supplies extra information about a core record. The number of records in each extension data table is illustrated below.