The role of phytoplankton dynamics in the seasonal and interannual variability of carbon in the subpolar North Atlantic – a modeling study
We developed an ecosystem/biogeochemical model system, which includes multiple phytoplankton functional groups and carbon cycle dynamics, and applied it to investigate physical-biological interactions in Icelandic waters. Satellite and in situ data were used to evaluate the model. Surface seasonal c...
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ftdoajarticles:oai:doaj.org/article:d2bea61e23814a39a192c284612adad5 2023-05-15T17:36:58+02:00 The role of phytoplankton dynamics in the seasonal and interannual variability of carbon in the subpolar North Atlantic – a modeling study S. R. Signorini S. Häkkinen K. Gudmundsson A. Olsen A. M. Omar J. Olafsson G. Reverdin S. A. Henson C. R. McClain D. L. Worthen 2012-05-01T00:00:00Z https://doi.org/10.5194/gmd-5-683-2012 https://doaj.org/article/d2bea61e23814a39a192c284612adad5 EN eng Copernicus Publications http://www.geosci-model-dev.net/5/683/2012/gmd-5-683-2012.pdf https://doaj.org/toc/1991-959X https://doaj.org/toc/1991-9603 doi:10.5194/gmd-5-683-2012 1991-959X 1991-9603 https://doaj.org/article/d2bea61e23814a39a192c284612adad5 Geoscientific Model Development, Vol 5, Iss 3, Pp 683-707 (2012) Geology QE1-996.5 article 2012 ftdoajarticles https://doi.org/10.5194/gmd-5-683-2012 2022-12-31T03:28:43Z We developed an ecosystem/biogeochemical model system, which includes multiple phytoplankton functional groups and carbon cycle dynamics, and applied it to investigate physical-biological interactions in Icelandic waters. Satellite and in situ data were used to evaluate the model. Surface seasonal cycle amplitudes and biases of key parameters (DIC, TA, p CO 2 , air-sea CO 2 flux, and nutrients) are significantly improved when compared to surface observations by prescribing deep water values and trends, based on available data. The seasonality of the coccolithophore and "other phytoplankton" (diatoms and dinoflagellates) blooms is in general agreement with satellite ocean color products. Nutrient supply, biomass and calcite concentrations are modulated by light and mixed layer depth seasonal cycles. Diatoms are the most abundant phytoplankton, with a large bloom in early spring and a secondary bloom in fall. The diatom bloom is followed by blooms of dinoflagellates and coccolithophores. The effect of biological changes on the seasonal variability of the surface ocean p CO 2 is nearly twice the temperature effect, in agreement with previous studies. The inclusion of multiple phytoplankton functional groups in the model played a major role in the accurate representation of CO 2 uptake by biology. For instance, at the peak of the bloom, the exclusion of coccolithophores causes an increase in alkalinity of up to 4 μmol kg −1 with a corresponding increase in DIC of up to 16 μmol kg −1 . During the peak of the bloom in summer, the net effect of the absence of the coccolithophores bloom is an increase in p CO 2 of more than 20 μatm and a reduction of atmospheric CO 2 uptake of more than 6 mmol m −2 d −1 . On average, the impact of coccolithophores is an increase of air-sea CO 2 flux of about 27%. Considering the areal extent of the bloom from satellite images within the Irminger and Icelandic Basins, this reduction translates into an annual mean of nearly 1500 tonnes C yr −1 . Article in Journal/Newspaper North Atlantic Directory of Open Access Journals: DOAJ Articles Geoscientific Model Development 5 3 683 707 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geology QE1-996.5 |
spellingShingle |
Geology QE1-996.5 S. R. Signorini S. Häkkinen K. Gudmundsson A. Olsen A. M. Omar J. Olafsson G. Reverdin S. A. Henson C. R. McClain D. L. Worthen The role of phytoplankton dynamics in the seasonal and interannual variability of carbon in the subpolar North Atlantic – a modeling study |
topic_facet |
Geology QE1-996.5 |
description |
We developed an ecosystem/biogeochemical model system, which includes multiple phytoplankton functional groups and carbon cycle dynamics, and applied it to investigate physical-biological interactions in Icelandic waters. Satellite and in situ data were used to evaluate the model. Surface seasonal cycle amplitudes and biases of key parameters (DIC, TA, p CO 2 , air-sea CO 2 flux, and nutrients) are significantly improved when compared to surface observations by prescribing deep water values and trends, based on available data. The seasonality of the coccolithophore and "other phytoplankton" (diatoms and dinoflagellates) blooms is in general agreement with satellite ocean color products. Nutrient supply, biomass and calcite concentrations are modulated by light and mixed layer depth seasonal cycles. Diatoms are the most abundant phytoplankton, with a large bloom in early spring and a secondary bloom in fall. The diatom bloom is followed by blooms of dinoflagellates and coccolithophores. The effect of biological changes on the seasonal variability of the surface ocean p CO 2 is nearly twice the temperature effect, in agreement with previous studies. The inclusion of multiple phytoplankton functional groups in the model played a major role in the accurate representation of CO 2 uptake by biology. For instance, at the peak of the bloom, the exclusion of coccolithophores causes an increase in alkalinity of up to 4 μmol kg −1 with a corresponding increase in DIC of up to 16 μmol kg −1 . During the peak of the bloom in summer, the net effect of the absence of the coccolithophores bloom is an increase in p CO 2 of more than 20 μatm and a reduction of atmospheric CO 2 uptake of more than 6 mmol m −2 d −1 . On average, the impact of coccolithophores is an increase of air-sea CO 2 flux of about 27%. Considering the areal extent of the bloom from satellite images within the Irminger and Icelandic Basins, this reduction translates into an annual mean of nearly 1500 tonnes C yr −1 . |
format |
Article in Journal/Newspaper |
author |
S. R. Signorini S. Häkkinen K. Gudmundsson A. Olsen A. M. Omar J. Olafsson G. Reverdin S. A. Henson C. R. McClain D. L. Worthen |
author_facet |
S. R. Signorini S. Häkkinen K. Gudmundsson A. Olsen A. M. Omar J. Olafsson G. Reverdin S. A. Henson C. R. McClain D. L. Worthen |
author_sort |
S. R. Signorini |
title |
The role of phytoplankton dynamics in the seasonal and interannual variability of carbon in the subpolar North Atlantic – a modeling study |
title_short |
The role of phytoplankton dynamics in the seasonal and interannual variability of carbon in the subpolar North Atlantic – a modeling study |
title_full |
The role of phytoplankton dynamics in the seasonal and interannual variability of carbon in the subpolar North Atlantic – a modeling study |
title_fullStr |
The role of phytoplankton dynamics in the seasonal and interannual variability of carbon in the subpolar North Atlantic – a modeling study |
title_full_unstemmed |
The role of phytoplankton dynamics in the seasonal and interannual variability of carbon in the subpolar North Atlantic – a modeling study |
title_sort |
role of phytoplankton dynamics in the seasonal and interannual variability of carbon in the subpolar north atlantic – a modeling study |
publisher |
Copernicus Publications |
publishDate |
2012 |
url |
https://doi.org/10.5194/gmd-5-683-2012 https://doaj.org/article/d2bea61e23814a39a192c284612adad5 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Geoscientific Model Development, Vol 5, Iss 3, Pp 683-707 (2012) |
op_relation |
http://www.geosci-model-dev.net/5/683/2012/gmd-5-683-2012.pdf https://doaj.org/toc/1991-959X https://doaj.org/toc/1991-9603 doi:10.5194/gmd-5-683-2012 1991-959X 1991-9603 https://doaj.org/article/d2bea61e23814a39a192c284612adad5 |
op_doi |
https://doi.org/10.5194/gmd-5-683-2012 |
container_title |
Geoscientific Model Development |
container_volume |
5 |
container_issue |
3 |
container_start_page |
683 |
op_container_end_page |
707 |
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1766136636840607744 |