Particle sources and downward fluxes in the eastern Fram strait under the influence of the west Spitsbergen current

• Published in: Deep Sea Research Part I: Oceanographic Research Papers
• Main Authors: Sanchez-Vidal, Anna, Veres, Oriol, Langone, Leonardo, Ferré, Benedicte, Calafat, Antoni, Canals, Miquel, Durrieu de Madron, Xavier, Heussner, Serge, Mienert, Jurgen, Grimalt, Joan O., Pusceddu, Antonio, Danovaro, Roberto
• Other Authors: GRC Geociències Marines, Department de Estratigrafía, Istituto di Scienze Marine Bologna (ISMAR), Istituto di Science Marine (ISMAR ), National Research Council of Italy, Centre for Arctic Gas Hydrate, Environment and Climate (CAGE), The Arctic University of Norway Tromsø, Norway (UiT), Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institute of Environmental Assessment and Water Research (IDAEA), Consejo Superior de Investigaciones Cientificas España = Spanish National Research Council Spain (CSIC), Department of Life and Environmental Sciences, Polytechnic University of Marche
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: Particle fluxes; Organic Carbon; Ice rafted detritus; West Spitsbergen current; Fram Strait; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Arctic; Arctic Ocean; Storfjordrenna; Phytoplankton; Sea ice; Spitsbergen
• Online Access: https://univ-perp.hal.science/hal-01167553; https://doi.org/10.1016/j.dsr.2015.06.002

International audience The carbon cycle of the Arctic Ocean is tightly regulated by land–atmosphere–cryosphere–ocean interactions. Characterizing these environmental exchanges and feedbacks is critical to facilitate projections of the carbon cycle under changing climate conditions. The environmental drivers of sinking particles including organic carbon (OC) to the deep-sea floor are investigated with four moorings including sediment traps and currentmeters at the Arctic gateway in the eastern Fram Strait, which is the area where warm anomalies are transported northwards to the Arctic. Particles fluxes were collected over one year (July 2010–July 2011) and have been analysed to obtain the content of the lithogenic fraction, calcium carbonate, OC and its stable isotopes, opal, and the grain size. Records of near bottom current speed and temperature along with satellite observations of sea ice extent and chlorophyll-a concentration have been used for evaluation of the environmental conditions.We found increased lithogenic fluxes (up to 9872 mg m−2 d−1) and coarsening grain size of settling particles in late winter–early spring. At the same time, intensifications of the northward flowing west Spitsbergen current (WSC) were recorded. The WSC was able to resuspend and transport northwards sediments that were deposited at the outlet of Storfjordrenna and on the upper slope west of Spitsbergen. The signal of recurrent winnowing of fine particles was also detected in the top layer of surface sediments. In addition, an increased arrival of sea ice transported ice rafted detritus (>414 detrital carbonate mineral grains larger than 1 mm per m2) from the southern Spitsbergen coast along with terrestrial organic matter was observed beyond 1000 m of water depth during winter months. Finally, the downward particle fluxes showed typical temporal variability of high latitudes, with high percentages of the biogenic compounds (opal, organic carbon and calcium carbonate) linked to the phytoplankton bloom in spring–summer. ...