scholarly journals Inferring phytoplankton carbon and eco-physiological rates from diel cycles of spectral particulate beam-attenuation coefficient

2011 ◽  
Vol 8 (2) ◽  
pp. 3009-3050 ◽  
Author(s):  
G. Dall'Olmo ◽  
T. K. Westberry ◽  
M. J. Behrenfeld ◽  
E. Boss ◽  
C. Courties ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Attenuation Coefficient ◽  
Ocean Carbon Cycle ◽  
Diel Cycles ◽  
Carbon Biomass ◽  
Beam Attenuation ◽  
Spherical Diameter ◽  
Ocean Carbon ◽  
Diel Variability ◽  
Beam Attenuation Coefficient

Abstract. The diurnal fluctuations in solar irradiance impose a fundamental frequency on ocean biogeochemistry. Observations of the ocean carbon cycle at these frequencies are rare, but could be considerably expanded by measuring and interpreting the inherent optical properties. A method is presented to analyze diel cycles in particulate beam-attenuation coefficient (cp) measured at multiple wavelengths. The method is based on fitting observations with a size-structured population and optical model to infer the particle size distribution and physiologically relevant parameters of the cells responsible for the measured diel cycle in cp. Results show that the information related to size and contained in the spectral data can be exploited to independently estimate growth and loss rates during the day and night. In addition, the model can characterize the population of particles affecting the cp diel variability. Application of this method to spectral cp measured at a station in the oligotrophic Mediterranean Sea suggests that most of the observed variations in cp can be ascribed to a synchronized population of cells with an equivalent spherical diameter between 1 and 4 μm. The inferred carbon biomass of these cells was about 8–13 mg m−3 and accounted for approximately 20% of the total particulate organic carbon. If successfully validated and implemented on autonomous platforms, this method could improve our understanding of the ocean carbon cycle.

scholarly journals Inferring phytoplankton carbon and eco-physiological rates from diel cycles of spectral particulate beam-attenuation coefficient

2011 ◽  
Vol 8 (11) ◽  
pp. 3423-3439 ◽  
Author(s):  
G. Dall'Olmo ◽  
E. Boss ◽  
M. J. Behrenfeld ◽  
T. K. Westberry ◽  
C. Courties ◽  
...  
Keyword(s):  
Attenuation Coefficient ◽  
Structured Population Model ◽  
Diel Cycles ◽  
Carbon Biomass ◽  
Beam Attenuation ◽  
Multiple Wavelengths ◽  
Spherical Diameter ◽  
Ocean Carbon ◽  
Diel Variability ◽  
Beam Attenuation Coefficient

Abstract. The diurnal fluctuations in solar irradiance impose a fundamental frequency on ocean biogeochemistry. Observations of the ocean carbon cycle at these frequencies are rare, but could be considerably expanded by measuring and interpreting the inherent optical properties. A method is presented to analyze diel cycles in particulate beam-attenuation coefficient (cp) measured at multiple wavelengths. The method is based on fitting observations with a size-structured population model coupled to an optical model to infer the particle size distribution and physiologically relevant parameters of the cells responsible for the measured diel cycle in cp. Results show that the information related to size and contained in the spectral data can be exploited to independently estimate growth and loss rates during the day and night. In addition, the model can characterize the population of particles affecting the diel variability in cp. Application of this method to spectral cp measured at a station in the oligotrophic Mediterranean Sea suggests that most of the observed variations in cp can be ascribed to a synchronized population of cells with an equivalent spherical diameter around 4.6±1.5 μm. The inferred carbon biomass of these cells was about 5.2–6.0 mg m−3 and accounted for approximately 10% of the total particulate organic carbon. If successfully validated, this method may improve our in situ estimates of primary productivity.

scholarly journals Changes in the Arctic Ocean carbon cycle with diminishing ice cover

2020 ◽  
Author(s):  
Michael D. DeGrandpre ◽  
Wiley Evans ◽  
Mary-Louise Timmermans ◽  
Richard A. Krishfield ◽  
William J Williams ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Arctic Ocean ◽  
Ice Cover ◽  
The Arctic ◽  
Ocean Carbon Cycle ◽  
The Arctic Ocean ◽  
Ocean Carbon

scholarly journals A fishy tale: A missing part of the inorganic ocean carbon cycle

2011 ◽  
Vol 33 (3) ◽  
pp. 30-34
Author(s):  
Rod W. Wilson ◽  
Erin E. Reardon ◽  
Christopher T. Perry
Keyword(s):  
Carbon Cycle ◽  
Ocean Acidification ◽  
Fossil Fuels ◽  
Sea Water ◽  
Atmospheric Co2 ◽  
Co2 Production ◽  
Ph Change ◽  
Ocean Carbon Cycle ◽  
Sea Levels ◽  
Ocean Carbon

Human activities, such as burning fossil fuels, are playing an important role in the rising levels of carbon dioxide (CO2) in the Earth's atmosphere1. The oceans may store a large portion of CO2 that we are releasing into the atmosphere, with up to 40% already taken up by the oceans. Although this absorption helps to offset some of the greenhouse effect of atmospheric CO2, it also contributes to ocean acidification, or a fall in the pH of sea water. The historical global mean pH of oceanic sea water is about 8.2, and this has already declined by 0.1 pH units (a 30% increase in H+ concentration) and is predicted to reach pH ~7.7 by the end of the century if current rates of fossil fuel use continue, leading to an atmospheric CO2 level of 800 p.p.m.1,2. Even this extreme potential fall in pH would still leave seawater above the neutral point (pH 7.0), so technically it is more accurate to say that the ocean is becoming less alkaline, rather than truly acidic (i.e. below pH 7.0). However, the magnitude is perhaps less important than the speed of pH change which is occurring faster than at any time during the previous 20 million years. Over this time, the average ocean pH has probably never fallen below pH 8.02,3. It is only during the last decade that the importance of ocean acidification has come to the forefront of concerns for scientists1,2. Consequences of these changes in global CO2 production are predicted to include elevated global temperatures, rising sea levels, more unpredictable and extreme weather patterns, and shifts in ecosystems1. In order to more fully understand the implications of ocean acidification, teams of researchers, including fisheries scientists, physiologists, geologists, oceanographers, chemists and climate modellers, are working to refine current understanding of the ocean carbon cycle.

Coccolith chemistry reveals secular variations in the global ocean carbon cycle?

2007 ◽  
Vol 253 (1-2) ◽  
pp. 83-95 ◽  
Author(s):  
R.E.M. Rickaby ◽  
E. Bard ◽  
C. Sonzogni ◽  
F. Rostek ◽  
L. Beaufort ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Global Ocean ◽  
Ocean Carbon Cycle ◽  
Secular Variations ◽  
Ocean Carbon

scholarly journals Ocean Carbon Cycle Feedbacks Under Negative Emissions

2018 ◽  
Vol 45 (10) ◽  
pp. 5062-5070 ◽  
Author(s):  
Jörg Schwinger ◽  
Jerry Tjiputra
Keyword(s):  
Carbon Cycle ◽  
Ocean Carbon Cycle ◽  
Negative Emissions ◽  
Ocean Carbon
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