Microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean
Marine aggregates are the vector for biogenically bound carbon and nutrients from the euphotic zone to the interior of the oceans. To improve the representation of this biological carbon pump in the global biogeochemical HAMburg Ocean Carbon Cycle (HAMOCC) model, we implemented a novel Microstructur...
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Copernicus Publications (EGU)
2020
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Online Access: | https://oceanrep.geomar.de/id/eprint/54780/ https://oceanrep.geomar.de/id/eprint/54780/1/bg-17-1765-2020.pdf https://doi.org/10.5194/bg-17-1765-2020 |
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ftoceanrep:oai:oceanrep.geomar.de:54780 2023-05-15T18:25:45+02:00 Microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean Maerz, Joeran Six, Katharina D. Stemmler, Irene Ahmerkamp, Soeren Ilyina, Tatiana 2020-04-03 text https://oceanrep.geomar.de/id/eprint/54780/ https://oceanrep.geomar.de/id/eprint/54780/1/bg-17-1765-2020.pdf https://doi.org/10.5194/bg-17-1765-2020 en eng Copernicus Publications (EGU) https://oceanrep.geomar.de/id/eprint/54780/1/bg-17-1765-2020.pdf Maerz, J., Six, K. D., Stemmler, I., Ahmerkamp, S. and Ilyina, T. (2020) Microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean. Open Access Biogeosciences, 17 (7). pp. 1765-1803. DOI 10.5194/bg-17-1765-2020 <https://doi.org/10.5194/bg-17-1765-2020>. doi:10.5194/bg-17-1765-2020 cc_by_4.0 info:eu-repo/semantics/openAccess Article PeerReviewed 2020 ftoceanrep https://doi.org/10.5194/bg-17-1765-2020 2023-04-07T16:00:18Z Marine aggregates are the vector for biogenically bound carbon and nutrients from the euphotic zone to the interior of the oceans. To improve the representation of this biological carbon pump in the global biogeochemical HAMburg Ocean Carbon Cycle (HAMOCC) model, we implemented a novel Microstructure, Multiscale, Mechanistic, Marine Aggregates in the Global Ocean (M4AGO) sinking scheme. M4AGO explicitly represents the size, microstructure, heterogeneous composition, density and porosity of aggregates and ties ballasting mineral and particulate organic carbon (POC) fluxes together. Additionally, we incorporated temperature-dependent remineralization of POC. We compare M4AGO with the standard HAMOCC version, where POC fluxes follow a Martin curve approach with (i) linearly increasing sinking velocity with depth and (ii) temperature-independent remineralization. Minerals descend separately with a constant speed. In contrast to the standard HAMOCC, M4AGO reproduces the latitudinal pattern of POC transfer efficiency, as recently constrained by Weber et al. (2016). High latitudes show transfer efficiencies of ≈0.25±0.04, and the subtropical gyres show lower values of about 0.10±0.03. In addition to temperature as a driving factor for remineralization, diatom frustule size co-determines POC fluxes in silicifier-dominated ocean regions, while calcium carbonate enhances the aggregate excess density and thus sinking velocity in subtropical gyres. Prescribing rising carbon dioxide (CO2) concentrations in stand-alone runs (without climate feedback), M4AGO alters the regional ocean atmosphere CO2 fluxes compared to the standard model. M4AGO exhibits higher CO2 uptake in the Southern Ocean compared to the standard run, while in subtropical gyres, less CO2 is taken up. Overall, the global oceanic CO2 uptake remains the same. With the explicit representation of measurable aggregate properties, M4AGO can serve as a test bed for evaluating the impact of aggregate-associated processes on global biogeochemical cycles and, in ... Article in Journal/Newspaper Southern Ocean OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Southern Ocean Biogeosciences 17 7 1765 1803 |
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Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
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ftoceanrep |
language |
English |
description |
Marine aggregates are the vector for biogenically bound carbon and nutrients from the euphotic zone to the interior of the oceans. To improve the representation of this biological carbon pump in the global biogeochemical HAMburg Ocean Carbon Cycle (HAMOCC) model, we implemented a novel Microstructure, Multiscale, Mechanistic, Marine Aggregates in the Global Ocean (M4AGO) sinking scheme. M4AGO explicitly represents the size, microstructure, heterogeneous composition, density and porosity of aggregates and ties ballasting mineral and particulate organic carbon (POC) fluxes together. Additionally, we incorporated temperature-dependent remineralization of POC. We compare M4AGO with the standard HAMOCC version, where POC fluxes follow a Martin curve approach with (i) linearly increasing sinking velocity with depth and (ii) temperature-independent remineralization. Minerals descend separately with a constant speed. In contrast to the standard HAMOCC, M4AGO reproduces the latitudinal pattern of POC transfer efficiency, as recently constrained by Weber et al. (2016). High latitudes show transfer efficiencies of ≈0.25±0.04, and the subtropical gyres show lower values of about 0.10±0.03. In addition to temperature as a driving factor for remineralization, diatom frustule size co-determines POC fluxes in silicifier-dominated ocean regions, while calcium carbonate enhances the aggregate excess density and thus sinking velocity in subtropical gyres. Prescribing rising carbon dioxide (CO2) concentrations in stand-alone runs (without climate feedback), M4AGO alters the regional ocean atmosphere CO2 fluxes compared to the standard model. M4AGO exhibits higher CO2 uptake in the Southern Ocean compared to the standard run, while in subtropical gyres, less CO2 is taken up. Overall, the global oceanic CO2 uptake remains the same. With the explicit representation of measurable aggregate properties, M4AGO can serve as a test bed for evaluating the impact of aggregate-associated processes on global biogeochemical cycles and, in ... |
format |
Article in Journal/Newspaper |
author |
Maerz, Joeran Six, Katharina D. Stemmler, Irene Ahmerkamp, Soeren Ilyina, Tatiana |
spellingShingle |
Maerz, Joeran Six, Katharina D. Stemmler, Irene Ahmerkamp, Soeren Ilyina, Tatiana Microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean |
author_facet |
Maerz, Joeran Six, Katharina D. Stemmler, Irene Ahmerkamp, Soeren Ilyina, Tatiana |
author_sort |
Maerz, Joeran |
title |
Microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean |
title_short |
Microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean |
title_full |
Microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean |
title_fullStr |
Microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean |
title_full_unstemmed |
Microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean |
title_sort |
microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean |
publisher |
Copernicus Publications (EGU) |
publishDate |
2020 |
url |
https://oceanrep.geomar.de/id/eprint/54780/ https://oceanrep.geomar.de/id/eprint/54780/1/bg-17-1765-2020.pdf https://doi.org/10.5194/bg-17-1765-2020 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
https://oceanrep.geomar.de/id/eprint/54780/1/bg-17-1765-2020.pdf Maerz, J., Six, K. D., Stemmler, I., Ahmerkamp, S. and Ilyina, T. (2020) Microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean. Open Access Biogeosciences, 17 (7). pp. 1765-1803. DOI 10.5194/bg-17-1765-2020 <https://doi.org/10.5194/bg-17-1765-2020>. doi:10.5194/bg-17-1765-2020 |
op_rights |
cc_by_4.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/bg-17-1765-2020 |
container_title |
Biogeosciences |
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17 |
container_issue |
7 |
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1765 |
op_container_end_page |
1803 |
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1766207402420469760 |