Marine productivity response to Heinrich events; a model-data comparison

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doi: 10.5194/cp-8-1581-2012
Author(s): Mariotti, Veronique; Bopp, Laurent; Tagliabue, Alessandro; Kageyama, Masa; Swingedouw, Didier
Author Affiliation(s): Primary:
CEA-CNRS-UVSQ, Institute Pierre Simon Laplace, Laboratoire des Sciences du Climat et de l'Environnement, Gif-sur-Yvette, France
Other:
University of Cape Town, South Africa
Council for Scientific and Industrial Research, South Africa
Volume Title: Climate of the Past
Source: Climate of the Past, 8(5), p.1581-1598. Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1814-9324
Note: In English. Includes supplement, http://www.clim-past.net/8/1581/2012/cp-8-1581-2012-supplement.pdf; published in Climate of the Past Discussion: 14 February 2012, http://www.clim-past-discuss.net/8/557/2012/cpd-8-557-2012.html; accessed in Feb., 2013. 102 refs.; illus., incl. 2 tables
Summary: Marine sediments records suggest large changes in marine productivity during glacial periods, with abrupt variations especially during the Heinrich events. Here, we study the response of marine biogeochemistry to such an event by using a biogeochemical model of the global ocean (PISCES) coupled to an ocean-atmosphere general circulation model (IPSL-CM4). We conduct a 400-yr-long transient simulation under glacial climate conditions with a freshwater forcing of 0.1 Sv applied to the North Atlantic to mimic a Heinrich event, alongside a glacial control simulation. To evaluate our numerical results, we have compiled the available marine productivity records covering Heinrich events. We find that simulated primary productivity and organic carbon export decrease globally (by 16% for both) during a Heinrich event, albeit with large regional variations. In our experiments, the North Atlantic displays a significant decrease, whereas the Southern Ocean shows an increase, in agreement with paleo-productivity reconstructions. In the Equatorial Pacific, the model simulates an increase in organic matter export production but decreased biogenic silica export. This antagonistic behaviour results from changes in relative uptake of carbon and silicic acid by diatoms. Reasonable agreement between model and data for the large-scale response to Heinrich events gives confidence in models used to predict future centennial changes in marine production. In addition, our model allows us to investigate the mechanisms behind the observed changes in the response to Heinrich events.
Year of Publication: 2012
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Africa; Algae; Ammonium; Arctic Ocean; Arctic region; Atlantic Ocean; Atmospheric transport; Benguela Current; Biochemistry; Carbon; Carbon dioxide; Cenozoic; Detroit Seamount; Diatoms; East Pacific; Ecosystems; Emperor Seamounts; Equatorial Pacific; Glacial environment; Greenland; Greenland ice sheet; Heinrich events; Holocene; Ice; Indian Ocean; Iron; Last glacial maximum; Leg 145; Leg 167; Leg 184; Leg 202; Marine sediments; Mauritania; Metals; Microfossils; Mineralization; Nitrates; North Atlantic; North Pacific; Northeast Pacific; Northwest Pacific; ODP Site 1019; ODP Site 1144; ODP Site 1233; ODP Site 1240; ODP Site 1242; ODP Site 882; ODP Site 887; Ocean Drilling Program; Organic carbon; Pacific Ocean; Paleoproductivity; Panama Basin; Particles; Particulate materials; Pelagic Interaction Scheme for Carbon and Ecosystem Studies; Phosphates; Photochemistry; Photosynthesis; Phytoplankton; Plankton; Plantae; Quaternary; Respiration; Sea ice; Sea-surface temperature; Sedimentation; Sediments; Silicic acid; Solutes; South China Sea; South Pacific; Southeast Pacific; Transport; Volcanism; West Africa; West Pacific; Winds; World ocean
Coordinates: N075100 N075100 W0833600 W0833600
N000100 N000100 W0822800 W0822800
Record ID: 2013043982
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Copernicus Gesellschaft, Katlenburg-Lindau, Germany