Phytoplankton acclimation to changing light intensity in a turbulent mixed layer: A Lagrangian modelling study
Phytoplankton acclimation to changing light intensity in a turbulent mixed layer: A Lagrangian modelling study
A new individual-based plankton model is used to test the hypothesis that the timescale of photoacclimation of phytoplankton within the surface mixing layer of the ocean is slow relative to mixing, in which case the chlorophyll to carbon (Chl:C) ratio of individual cells shows little adjustment in response to changes in light environment driven by vertical displacement. Rates of photoacclimation are shown to be a strongly non-linear function of light intensity that depends on the balance of intrinsic chlorophyll synthesis at low irradiance versus increasing growth rate at high irradiance. Predicted photoacclimation was negligible for cells experiencing rates of turbulent mixing typical of the open ocean surface boundary layer (10−3 to 10-1 m2 s-1), in which case Chl:C is set by mean light intensity. The model was extended to incorporate a simple ecosystem of nutrient, phytoplankton, zooplankton and detritus and, using two-layer slab physics, used to study photoacclimation in a more realistic setting, the seasonal cycle of plankton dynamics at Ocean Weather Station India in the North Atlantic (59 °N, 20 °W). Results were remarkably similar when compared with an equivalent ecosystem model that used an Eulerian representation of phytoplankton, reinforcing our conclusion that mixing rates within the surface mixed layer of the ocean are typically too fast to permit photoacclimation by phytoplankton to ambient light.
Carbon to chlorophyll, Individual-based model, Lagrangian model, Marine ecosystem, Photoacclimation, Primary production
Tomkins, Melissa
ef72651d-dfd9-45d4-984f-3439f9fae456
Martin, Adrian P.
9d0d480d-9b3c-44c2-aafe-bb980ed98a6d
Nurser, A.j. George
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Anderson, Thomas R.
dfed062f-e747-48d3-b59e-2f5e57a8571d
1 February 2020
Tomkins, Melissa
ef72651d-dfd9-45d4-984f-3439f9fae456
Martin, Adrian P.
9d0d480d-9b3c-44c2-aafe-bb980ed98a6d
Nurser, A.j. George
2493ef9a-21e9-4d8b-9c32-08677e7e145a
Anderson, Thomas R.
dfed062f-e747-48d3-b59e-2f5e57a8571d
Tomkins, Melissa, Martin, Adrian P., Nurser, A.j. George and Anderson, Thomas R.
(2020)
Phytoplankton acclimation to changing light intensity in a turbulent mixed layer: A Lagrangian modelling study.
Ecological Modelling, 417, [108917].
(doi:10.1016/j.ecolmodel.2019.108917).
Abstract
A new individual-based plankton model is used to test the hypothesis that the timescale of photoacclimation of phytoplankton within the surface mixing layer of the ocean is slow relative to mixing, in which case the chlorophyll to carbon (Chl:C) ratio of individual cells shows little adjustment in response to changes in light environment driven by vertical displacement. Rates of photoacclimation are shown to be a strongly non-linear function of light intensity that depends on the balance of intrinsic chlorophyll synthesis at low irradiance versus increasing growth rate at high irradiance. Predicted photoacclimation was negligible for cells experiencing rates of turbulent mixing typical of the open ocean surface boundary layer (10−3 to 10-1 m2 s-1), in which case Chl:C is set by mean light intensity. The model was extended to incorporate a simple ecosystem of nutrient, phytoplankton, zooplankton and detritus and, using two-layer slab physics, used to study photoacclimation in a more realistic setting, the seasonal cycle of plankton dynamics at Ocean Weather Station India in the North Atlantic (59 °N, 20 °W). Results were remarkably similar when compared with an equivalent ecosystem model that used an Eulerian representation of phytoplankton, reinforcing our conclusion that mixing rates within the surface mixed layer of the ocean are typically too fast to permit photoacclimation by phytoplankton to ambient light.
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More information
Accepted/In Press date: 11 December 2019
e-pub ahead of print date: 7 January 2020
Published date: 1 February 2020
Keywords:
Carbon to chlorophyll, Individual-based model, Lagrangian model, Marine ecosystem, Photoacclimation, Primary production
Identifiers
Local EPrints ID: 437826
URI: http://eprints.soton.ac.uk/id/eprint/437826
ISSN: 0304-3800
PURE UUID: c3fbf967-1da1-4516-b7e7-bbbcc76358ed
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Date deposited: 19 Feb 2020 17:32
Last modified: 16 Mar 2024 06:29
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Contributors
Author:
Melissa Tomkins
Author:
Adrian P. Martin
Author:
A.j. George Nurser
Author:
Thomas R. Anderson
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