Phytoplankton biomass and composition variability within different biogeochemical regimes in the N. Atlantic during the 2014 Ship-Aircraft Bio-Optical Research (SABOR) experiment

In order to determine the particulate organic carbon (POC) distribution in the surface ocean the development of ecosystem-based remote sensing algorithms are essential for monitoring and validating POC distributions derived from of satellite data products (i.e. MODIS). In a recent NASA funded Ship-Aircraft Bio-Optical Research experiment (SABOR), a coordinated multi-institutional effort was implemented to improve both in-situ, aircraft and satellite based measurements of oceanic particles, including phytoplankton, from optical measurements obtained during the 2014 SABOR research cruise. Using both flow cytometry and imaging cytometry (FlowCam^®; Fluid Imaging Technologies) phytoplankton abundance, biomass, composition and size distribution were determined for both pico/nano-phytoplankton and micro-phytoplankton, respectively, during the research experiment. The cruise track spanned many different biochemical regimes ranging from optically complex coastal environments along the continental shelf (i.e. Gulf of Maine), to oligotrophic off shore environments within the North Atlantic gyre. Significant variability in the particle size distribution (PSD) and the associated phytoplankton biomass and community composition were observed along the cruise track. In addition, total chlorophyll a, pigments, particulate organic carbon (POC), and optical parameters, including particulate optical backscattering coefficients were determined and assessed for comparison and to establish relationships between optical parameters and POC.