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Seasonal to Interannual Variability in Phytoplankton Biomass and Diversity on the New England Shelf. In Situ Time Series for Validation and Exploration of Remote Sensing Algorithms. Woods Hole Oceanographic Institution . University of New Hampshire. Heidi M. Sosik Hui Feng.
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Seasonal to Interannual Variability in Phytoplankton Biomass and Diversity on the New England Shelf In Situ Time Series for Validation and Exploration of Remote Sensing Algorithms Woods Hole Oceanographic Institution University of New Hampshire Heidi M. SosikHuiFeng
Project Overview Goal: Use unique time series to evaluate algorithms that extend MODIS ocean color data beyond chlorophyll to functional type or size-class-dependent phytoplankton retrievals Approach: End-to-end time series observations, with step-by-step algorithm evaluation and error analysis single cells phytoplankton community bulk water optical properties sea surface optical properties (air and water) MODIS optical properties Martha’s Vineyard Coastal Observatory Tower mounted AERONET-OC Submersible Imaging Flow Cytometry MODIS products
Approach Phytoplankton Observations Single cells to communities Biomass, size- and taxon-resolved Phytoplankton Algorithms Absorption spectral shape size structure Diagnostic pigments size structure Diagnostic pigments taxonomic structure
Variability in community structure . m m Diatoms Cyano- bacteria m m m m m m m m
Pigment-based retrieval of taxonomic groups Diatoms In situ FCM “CHEMTAX” Mackey et al. 1996 Total Chl a = diatom Chl a + dinoflagellateChl a + cyanobacteria Chl a + … with partitioning according to accessory pigment ratios
Pigment-based retrieval of taxonomic groups Diatoms Diatoms (mg m3)
Pigment-based retrieval of taxonomic groups Diatoms Dinoflagellates Cyanobacteria ~1 mm cells 10 mm
Pigment-based retrieval of taxonomic groups Diatoms Dinoflagellates Cyanobacteria Chl or Carbon (mg m3) ~1 mm cells 10 mm
Diagnostic pigment retrieval from Rrs Pan et al. 2010 band ratio algorithms AERONET-OC SeaPRISM, Rrs(l) Chl a Fucoxanthin Discrete samples HPLC pigment analysis Zeaxanthin Peridinin
Pigment-based retrieval of taxonomic groups Diatoms Dinoflagellates Cyanobacteria Chl or Carbon (mg m3) ~1 mm cells 10 mm
Remote sensing retrieval of taxonomic groups Diatoms Dinoflagellates Cyanobacteria Chl or Carbon (mg m3) AERONET-OC SeaPRISM, Rrs(l) Loss of seasonal resolution Following: Pan et al. 2010 band ratio algorithms Pan et al. 2011 CHEMTAX application
Remote sensing retrieval of taxonomic groups Diatoms Dinoflagellates Cyanobacteria Fraction of Chl a Relative contribution to total Chl a AERONET-OC SeaPRISM, Rrs(l) Loss of seasonal resolution Following: Pan et al. 2010 band ratio algorithms Pan et al. 2011 CHEMTAX application
Remote sensing retrieval of taxonomic groups Diatoms Dinoflagellates Cyanobacteria Fraction of Chl a Fraction of Chl a
Ecosystem characterization . Decadal increase in pico-cyanobacteria at MVCO
Ecosystem characterization . Peacock et al. 2014 50 mm
Ecosystem characterization . Peacock et al. 2014 Interannual fluctuations in diatoms related to parasite infection linked to temperature
Looking forward on PFT characterization Time series observations single cells phytoplankton community bulk water optical properties sea surface optical properties (air and water) MODIS optical properties Local detail Trends and patterns of change Regional to basin scales Martha’s Vineyard Coastal Observatory Tower mounted AERONET-OC MODIS products Combined in situ & satellite observations Submersible Imaging Flow Cytometry
http://ifcb-data.whoi.edu/ Open data access Standard formats Processing pipelines End-to-end provenance
Ecosystem characterization Cyanobacterium Diatoms Taxa with positive response to warmer winters Taxa with negative response to warmer winters Interannual variability – taxon specific Seasonally adjusted Biomass anomalies vs Temperature anomalies
Observing Phytoplankton at MVCO Martha’s Vineyard Coastal Observatory (MVCO) Cabled site with power and two-way communications Picoplankton Microplankton Automated features for extended deployment (>6 months) Enumeration, identification, and cell sizing Thousands of individual cells every hour FlowCytobot Imaging FlowCytobot Laser-based flow cytometry Fluorescence and light scattering Flow cytometry with video imaging Olson & Sosik 2007 Olson et al. 2003
Single Cells to Biomass Picoplankton Cell volume (mm3) FlowCytobot Menden-Deuer and Lessard 2000 Light scattering Volume from laser scattering Olson et al. 2003 Microplankton Imaging FlowCytobot Volume from image analysis new “distance map” approach Sosik and Olson 2007 Moberg & Sosik 2012