Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Biogeosciences, 13, 4205-4218, 2016
http://www.biogeosciences.net/13/4205/2016/
doi:10.5194/bg-13-4205-2016
© Author(s) 2016. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
25 Jul 2016
Sedimentary response to sea ice and atmospheric variability over the instrumental period off Adélie Land, East Antarctica
Philippine Campagne1,2,3,4, Xavier Crosta1, Sabine Schmidt1, Marie Noëlle Houssais2, Olivier Ther1, and Guillaume Massé2,3 1EPOC, UMR CNRS 5805, Université de Bordeaux, Allée Geoffroy St Hilaire, 33615 Pessac, France
2LOCEAN, UMR CNRS/UPCM/IRD/MNHN 7159, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris, France
3TAKUVIK, UMI 3376 UL/CNRS, Département de Biologie, Université Laval, G1V 0A6 Quebec (Quebec), Canada
4Québec-Océan, Université Laval, 1045 Avenue de la Médecine, G1V 0A6 Quebec (Quebec), Canada
Abstract. Diatoms account for a large proportion of primary productivity in Antarctic coastal and continental shelf zones. Diatoms, which have been used for a long time to infer past sea surface conditions in the Southern Ocean, have recently been associated with diatom-specific biomarkers (highly branched isoprenoids, HBI). Our study is one of the few sedimentary research projects on diatom ecology and associated biomarkers in the Antarctic seasonal sea ice zone. To date, the Adélie Land region has received little attention, despite evidence for the presence of high accumulation of laminated sediment, allowing for finer climate reconstructions and sedimentary process studies. Here we provide a sequence of seasonally to annually laminated diatomaceous sediment from a 72.5 cm interface core retrieved on the continental shelf off Adélie Land, covering the 1970–2010 CE period. Investigations through statistical analyses of diatom communities, diatom-specific biomarkers and major element abundances document the relationships between these proxies at an unprecedented resolution. Additionally, comparison of sedimentary records to meteorological data monitored by automatic weather station and satellite derived sea ice concentrations help to refine the relationships between our proxies and environmental conditions over the last decades. Our results suggest a coupled interaction of the atmospheric and sea surface variability on sea ice seasonality, which acts as the proximal forcing of siliceous productivity at that scale.

Citation: Campagne, P., Crosta, X., Schmidt, S., Noëlle Houssais, M., Ther, O., and Massé, G.: Sedimentary response to sea ice and atmospheric variability over the instrumental period off Adélie Land, East Antarctica, Biogeosciences, 13, 4205-4218, doi:10.5194/bg-13-4205-2016, 2016.
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Short summary
Diatoms and biomarkers have been recently used for palaeoclimate reconstructions in the Southern Ocean. Few sediment-based ecological studies have investigated their relationships with environmental conditions. Here, we compare high-resolution sedimentary records with meteorological data to study relationships between our proxies and recent atmospheric and sea surface changes. Our results indicate that coupled wind pattern and sea surface variability act as the proximal forcing at that scale.
Diatoms and biomarkers have been recently used for palaeoclimate reconstructions in the Southern...
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