Intercomparison of Marine Ecosystem Structure and Phenology in Global Biogeochemical Models
Saux Picart, Stephane1; Racault, Marie-Fanny1; Allen, Icarus1; Butenschon, Momme1; de Mora, Lee1; Yool, Andy2; Buitenhuis, Erik3; Totterdell, Ian4
1Plymouth Marine Laboratory, UNITED KINGDOM; 2NOC, UNITED KINGDOM; 3UEA, UNITED KINGDOM; 4MetOffice, UNITED KINGDOM
Phytoplankton community structure and phenology are two ecological indicators of prime importance for water quality assessment and climate/anthropogenic impact studies on marine ecosystem. Relationship have been evidenced between total chlorophyll-a concentration and diagnostic pigments specific to phytoplankton functional types. These relationship have been applied to chlorophyll concentrations estimated from ocean colour remote sensing to derive phytoplankton functional types. The continuity and length of these ocean-colour time-series have also permitted to depict the phenology of phytoplankton in the global oceans.
In the context of this study, we have derived diatom fraction and phenology from composite fields of chlorophyll provided by ESA - Ocean Colour Climate Change Initiative project.
Marine ecosystem models provide an invaluable tool to carry out impact studies and hence they are to subject to international scrutiny. In the framework of the iMarNet project (Integrated Marine Biogeochemical Modelling Network), five different biogeochemical models (having various degree of complexity) coupled with the same hydrodynamic model have been run in the same conditions. These runs have been performed at global scale and provide a unique opportunity to assess the capacity of models to inform about and predict the structure and functioning of marine ecosystem.
In the present study, we test the ability of the model to reproduce the relationship between total chlorophyll-a concentration and diatom concentration in different provinces of the world oceans. We also compare phytoplankton and diatoms phenologies from remote-sensing and the five models.