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RESEARCH ARTICLE
Contents Vol 58(10)

The effect of packaging of chlorophyll within phytoplankton and light scattering in a coupled physical–biological ocean model

Mark E. Baird A B , Patrick G. Timko A and Lujia Wu A
+ Author Affiliations
- Author Affiliations

A Climate Change Research Centre, School of Mathematics and Statistics, University of New South Wales, Sydney, NSW 2052, Australia.

B Corresponding author. Email: m.baird@unsw.edu.au

Marine and Freshwater Research 58(10) 966-981 https://doi.org/10.1071/MF07055
Submitted: 18 June 2007  Accepted: 14 September 2007   Published: 31 October 2007

Abstract

A coupled physical–biological model forced with spectrally resolved solar radiation is used to investigate the effect of packaging of pigment and light scattering on physical and biological properties in the open ocean. Simulations are undertaken with three alternate formulations of vertical attenuation, which consider: (1) chlorophyll as dissolved in the water column; (2) chlorophyll packaged into phytoplankton cells with no scattering; and (3) packaged chlorophyll with scattering. In the coupled model, depth-resolved solar heating depends on the vertical profile of phytoplankton concentration, creating a feedback mechanism between the physical and biological states.

The particular scenario investigated is a northerly wind off the coast of south-east Australia. The packaging of chlorophyll approximately halves the attenuation rate of 340–500 nm light and a phytoplankton maximum forms ~10 m deeper than in the dissolved chlorophyll case, with a corresponding adjustment of the dissolved inorganic nitrogen and zooplankton fields. Scattering approximately doubles the vertical attenuation of 340–600 nm light, lifting the phytoplankton maximum by ~10 m when compared with the packaged chlorophyll case. Additionally, strong horizontal gradients in chlorophyll distribution associated with filaments of upwelled water inshore of the East Australian Current, when modelled with alternate formulations of vertical light attenuation, result in circulation changes. The explicit representation of the packaging of pigment and light scattering is worth considering in coupled physical–biological modelling studies.

Additional keywords: biological induced heating, East Australian Current, light scattering, package effect, Port Stephens.


Acknowledgements

This research was funded by ARC Discovery Projects DP0557618 held by MB and DP0208663 held by Jason Middleton (UNSW). Analysis of the model output for a lower resolution configuration was undertaken in partial fulfilment of Lujia Wu’s Honours thesis at the UNSW. The use of the Australian Partnership for Advanced Computing (APAC) supercomputer, is gratefully acknowledged. We thank Alan Blumberg and George Mellor for the free availability of the Princeton Ocean Model (POM), and Patrick Marchesiello and Peter Oke for earlier work on the POM configuration for the waters off south-east Australia.


References

Armstrong, R. A. (2003). A hybrid spectral representation of phytoplankton growth and zooplankton response: the control rod model of planktonic interaction. Deep-Sea Research. Part II, Topical Studies in Oceanography 50, 2895–2916.
| Crossref | GoogleScholarGoogle Scholar | Atkins P. W. (1994). ‘Physical Chemistry,’ 5th edn. (Oxford University Press: Oxford.)

Baird, M. E. (2003). Numerical approximations of the mean absorption cross-section of a variety of randomly oriented microalgal shapes. Journal of Mathematical Biology 47, 325–336.
| Crossref | GoogleScholarGoogle Scholar | PubMed | Blumberg A. F., and Mellor G. L. (1987). A description of a three-dimensional coastal ocean circulation model. In ‘Three-dimensional Coastal Ocean Models’. (Ed. N. Heaps.) pp. 1–15. (American Geophysical Union: Washington, DC.)

Brock, T. D. (1981). Calculating solar radiation for ecological studies. Ecological Modelling 14, 1–19.
| Crossref | GoogleScholarGoogle Scholar | Kirk J. T. O. (1994). ‘Light and Photosynthesis in Aquatic Ecosystems,’ 2nd edn. (Cambridge University Press: Cambridge.)

Kistler, R. , Kalnay, E. , Collins, W. , Saha, S. , and White, G. , et al. (2001). The NCEP-NCAR 50-year reanalysis: monthly means CD-rom and documentation. Bulletin of the American Meteorological Society 82, 247–267.
| Crossref | GoogleScholarGoogle Scholar | Koller L. R. (1965). ‘Ultraviolet Radiation,’ 2nd edn. (John Wiley and Sons, Inc.: New York.)

Lewis, M. R. , Cullen, J. J. , and Platt, T. (1983). Phytoplankton and thermal structure in the upper ocean: consequences of nonuniformity in chlorophyll profile. Journal of Geophysical Research 88, 2565–2570.
Mishchenko M. I., Travis L. D., and Lacis A. A. (2002). ‘Scattering, Absorption and Emission of Light by Small Particles.’ (Cambridge University Press: Cambridge.)

Moloney, C. L. , and Field, J. G. (1991). The size-based dynamics of plankton food webs. I. A simulation model of carbon and nitrogen flows. Journal of Plankton Research 13, 1003–1038.
| Crossref | GoogleScholarGoogle Scholar | Pacanowski R. (1995). MOM2 Documentation User’s Guide and Reference Manual: GFDL Ocean Group Technical Report. Geophysical Fluid Dynamics Laboratory (GFDL), National Oceanic and Atmospheric Administration, Princeton, NJ.

Pegau S., Zanefeld J., Mitchell B., Mueller J., Kahru M., Wieland J., and Stramska M. (2003). Ocean Optics Protocols for Satellite Ocean Color Sensor Validation, Revision 4, Volume IV: Inherent Optical Properties: Instruments, Characterization, Field Measurements and Data Analysis Protocols. NASA/TM-2003-211621/Rev4-Vol. IV. Technical Report. (Eds J. L. Mueller, G. S. Fargion and C. R. McClain.) NASA Goddard Space Flight Center, Greenbelt, MD.

Redfield A. C., Ketchum B. H., and Richards F. A. (1963). The influence of organisms on the composition of sea-water. In ‘The Sea’, 2nd edn. (Ed. N. Hill.) pp. 26–77. (Wiley: New York.)

Roughan, M. , and Middleton, J. H. (2002). A comparison of observed upwelling mechanisms off the east coast of Australia. Continental Shelf Research 22, 2551–2572.
| Crossref | GoogleScholarGoogle Scholar |

Sathyendranath, S. , Prieur, L. , and Morel, A. (1989). A three-component model of ocean colour and its application to remote sensing of phytoplankton pigments in coastal waters. International Journal of Remote Sensing 10, 1373–1394.
| Crossref | GoogleScholarGoogle Scholar |

Smith, R. C. , and Baker, K. S. (1981). Optical properties of the clearest natural waters. Applied Optics 20, 177–184.


Stramska, M. , and Dickey, T. D. (1993). Phytoplakton bloom and the vertical thermal structure of the upper ocean. Journal of Marine Research 51, 819–842.
| Crossref | GoogleScholarGoogle Scholar |