American Geophysical Union Become an AGU Member
Subscribe to AGU Journals		 AGU Home AGU Publications

Read Full Article (file size: 621657 bytes)    Cited by

GLOBAL BIOGEOCHEMICAL CYCLES, VOL. 19, GB1006, doi:10.1029/2004GB002299, 2005

Carbon-based ocean productivity and phytoplankton physiology from space

Michael J. Behrenfeld

National Aeronautic and Space Administration, Goddard Space Flight Center, Greenbelt, Maryland, USA


Emmanuel Boss

School of Marine Sciences, University of Maine, Orono, Maine, USA


David A. Siegel

Institute for Computational Earth System Science, University of California, Santa Barbara, California, USA


Donald M. Shea

Science Applications International Corporation, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA


Abstract

Ocean biogeochemical and ecosystem processes are linked by net primary production (NPP) in the ocean's surface layer, where inorganic carbon is fixed by photosynthetic processes. Determinations of NPP are necessarily a function of phytoplankton biomass and its physiological status, but the estimation of these two terms from space has remained an elusive target. Here we present new satellite ocean color observations of phytoplankton carbon (C) and chlorophyll (Chl) biomass and show that derived Chl:C ratios closely follow anticipated physiological dependencies on light, nutrients, and temperature. With this new information, global estimates of phytoplankton growth rates (μ) and carbon-based NPP are made for the first time. Compared to an earlier chlorophyll-based approach, our carbon-based values are considerably higher in tropical oceans, show greater seasonality at middle and high latitudes, and illustrate important differences in the formation and demise of regional algal blooms. This fusion of emerging concepts from the phycological and remote sensing disciplines has the potential to fundamentally change how we model and observe carbon cycling in the global oceans.

Received 21 May 2004; accepted 2 November 2004; published 25 January 2005.

Keywords: phytoplankton; remote sensing; carbon; growth rates; productivity.

Index Terms: 4806 Oceanography: Biological and Chemical: Carbon cycling (0428); 4890 Oceanography: Biological and Chemical: Zooplankton; 4853 Oceanography: Biological and Chemical: Photosynthesis; 4855 Oceanography: Biological and Chemical: Phytoplankton.

Read Full Article (file size: 621657 bytes)    Cited by

Citation: Behrenfeld, M. J., E. Boss, D. A. Siegel, and D. M. Shea (2005), Carbon-based ocean productivity and phytoplankton physiology from space, Global Biogeochem. Cycles, 19, GB1006, doi:10.1029/2004GB002299.