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Titel |
Satellite-detected fluorescence reveals global physiology of ocean phytoplankton |
VerfasserIn |
M. J. Behrenfeld, T. K. Westberry, E. S. Boss, R. T. O'Malley, D. A. Siegel, J. D. Wiggert, B. A. Franz, C. R. McClain, G. C. Feldman, S. C. Doney, J. K. Moore, G. Dall'Olmo, A. J. Milligan, I. Lima, N. Mahowald |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 6, no. 5 ; Nr. 6, no. 5 (2009-05-08), S.779-794 |
Datensatznummer |
250003742
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Publikation (Nr.) |
copernicus.org/bg-6-779-2009.pdf |
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Zusammenfassung |
Phytoplankton photosynthesis links global ocean biology and climate-driven
fluctuations in the physical environment. These interactions are largely
expressed through changes in phytoplankton physiology, but physiological
status has proven extremely challenging to characterize globally.
Phytoplankton fluorescence does provide a rich source of physiological
information long exploited in laboratory and field studies, and is now
observed from space. Here we evaluate the physiological underpinnings of
global variations in satellite-based phytoplankton chlorophyll fluorescence.
The three dominant factors influencing fluorescence distributions are
chlorophyll concentration, pigment packaging effects on light absorption,
and light-dependent energy-quenching processes. After accounting for these
three factors, resultant global distributions of quenching-corrected
fluorescence quantum yields reveal a striking consistency with anticipated
patterns of iron availability. High fluorescence quantum yields are
typically found in low iron waters, while low quantum yields dominate
regions where other environmental factors are most limiting to phytoplankton
growth. Specific properties of photosynthetic membranes are discussed that
provide a mechanistic view linking iron stress to satellite-detected
fluorescence. Our results present satellite-based fluorescence as a valuable
tool for evaluating nutrient stress predictions in ocean ecosystem models
and give the first synoptic observational evidence that iron plays an
important role in seasonal phytoplankton dynamics of the Indian Ocean.
Satellite fluorescence may also provide a path for monitoring
climate-phytoplankton physiology interactions and improving descriptions of
phytoplankton light use efficiencies in ocean productivity models. |
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