Contrasting Export of Particulate Organic Carbon From Greenlandic Glacial and Nonglacial Streams

• Published in: Geophysical Research Letters
• Main Authors: Bröder, Lisa, Hirst, Catherine, Opfergelt, Sophie, Thomas, M., Vonk, Jorien, E., Haghipour, Negar, Eglinton, Timothy Ian, Fouché, Julien
• Other Authors: Geological Institute ETH Zürich, Department of Earth Sciences Swiss Federal Institute of Technology - ETH Zürich (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich), Earth and Life Institute Louvain-La-Neuve (ELI), Université Catholique de Louvain = Catholic University of Louvain (UCL), Ion Beam Physics ETH Zürich, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich), Laboratoire d'étude des Interactions Sol - Agrosystème - Hydrosystème (UMR LISAH), Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), The authors received funding for the field campaign from INTERACT under the European Union H2020 Grant 871120 to L.B. Further funding for this work came from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (ERC Starting Grant,714617) to S.O. and (ERC Starting Grant,Thawsome, Grant 676982) to J.V. Lastbut not least
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: [SDE.MCG]Environmental Sciences/Global Changes; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; Arctic; Greenland; Greenland Icecap; Hilton; greenlandic; permafrost; Phytoplankton
• Online Access: https://hal.science/hal-03885003; https://hal.science/hal-03885003/document; https://hal.science/hal-03885003/file/Br%C3%B6der%20et%20al.%20-%202022%20-%20Contrasting%20Export%20of%20Particulate%20Organic%20Carbon%20F.pdf; https://doi.org/10.1029/2022gl101210

International audience With rising temperatures, glaciers are retreating globally. The Greenland icecap has experienced record melt in the past decade (The IMBIE Team, 2020), amplifying freshwater discharge and transport of sediment and dissolved constituents (Hawkings et al., 2015; Meire et al., 2016). Cascading effects on downstream ecosystems remain uncertain, as additional nutrient input could enhance primary productivity in marine environments (e.g., Arrigo et al., 2017; Meire et al., 2017). Conversely, increased turbidity caused by the generally high suspended sediment loads of glacial outflow limits light penetration and thereby suppresses phytoplankton growth (Holding et al., 2019; Hopwood et al., 2020). In addition, retreating icecaps and glaciers expose previously covered landscapes to erosion, generally causing elevated sediment release until stabilization by colonizing vegetation (e.g., Ballantyne, 2002). Erosion rates are projected to increase throughout the Arctic due to rapid thaw and destabilization of permafrost (e.g., Hugelius et al., 2020; Olefeldt et al., 2016; Turetsky et al., 2020), as well as intensifying rain events caused by a shift from snow-to rain-dominated precipitation (e.g., Bintanja & Andry, 2017). Erosion of soils or recent vegetation litter can act as a carbon sink on geological timescales if the released organic carbon (OC) is rapidly buried in marine sediments (e.g., Hilton et al., 2015; Hovius et al., 2011). On the other hand, erosion constitutes a carbon source to the atmosphere if ancient permafrost soil or rock-derived (petrogenic) carbon is mineralized during transport or in marine environments (e.g.