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Geostationary satellite observations of dynamic phytoplankton photophysiology
Author(s) -
O'Malley Robert T.,
Behrenfeld Michael J.,
Westberry Toby K.,
Milligan Allen J.,
Shang Shaoling,
Yan Jing
Publication year - 2014
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2014gl060246
Subject(s) - phytoplankton , environmental science , geostationary orbit , satellite , irradiance , chlorophyll fluorescence , atmospheric sciences , oceanography , climatology , chlorophyll , geology , physics , biology , ecology , astronomy , botany , nutrient , quantum mechanics
Abstract Since June 2010, the Geostationary Ocean Color Imager (GOCI) has been collecting the first diurnally resolved satellite ocean measurements. Here GOCI retrievals of phytoplankton chlorophyll concentration and fluorescence are used to evaluate daily to seasonal changes in photophysiological properties. We focus on nonphotochemical quenching (NPQ) processes that protect phytoplankton from high light damage and cause strong diurnal cycles in fluorescence emission. This NPQ signal varies seasonally, with maxima in winter and minima in summer. Contrary to expectations from laboratory studies under constant light conditions, this pattern is highly consistent with an earlier conceptual model and recent field observations. The same seasonal cycle is registered in fluorescence data from the polar‐orbiting Moderate Resolution Imaging Spectroradiometer Aqua satellite sensor. GOCI data reveal a strong correlation between mixed layer growth irradiance and fluorescence‐derived phytoplankton photoacclimation state that can provide a path for mechanistically accounting for NPQ variability and, subsequently, retrieving information on iron stress in global phytoplankton populations.