Development and Evaluation of New Statistical Calibration Methods for Multi-Model Ensemble Week 3-4 Probabilistic Forecasts

OUTCOMES: We generated a framework for dynamic delineation of phytoplankton habitats in river plumes and outlying oceanic waters and evaluated the phytoplankton communities that occupy them.  The method is based on five biologically relevant and yet commonly measured environmental variables ? sea surface temperature, sea surface salinity, mixed layer depth, depth of the chlorophyll maximum, and nitrate availability to the euphotic zone.  These variables span both conservative and emergent properties of a system, meaning that this approach is both simple to implement and widely applicable.  When applied to the Amazon River plume, we identified seven niches ? river input (RI), young plume core (YPC), old plume core (OPC), western plume margin (WPM), eastern plume margin (EPM), and oceanic water (OSW).  Using data from three previous cruises in addition to the two conducted as a part of this project showed that these niches are robust across years and seasons.  Our habitat classifications were consistent with major patterns of the phytoplankton community composition in the Amazon River Plume region, generating consistent niches that support distinct phytoplankton communities. These community differences were most clear at the high taxonomic level captured by HPLC diagnostic pigments and in-vivo fluorescence measurements made with CLASS.  Group-specific direct counts differed less among habitats, which may reflect a mismatch between often rapid changes in physical and chemical properties and the growth responses of the phytoplankton communities.