FN Archimer Export Format PT J TI Iron isotope systematics in Arctic rivers BT AF ESCOUBE, Raphaelle ROUXEL, Olivier POKROVSKY, Oleg S. SCHROTH, Andrew HOLMES, Robert Max DONARD, Olivier F. X. AS 1:1,2,9;2:2,3;3:4,5,6;4:7;5:8;6:1; FF 1:;2:PDG-REM-GM-LCG;3:;4:;5:;6:; C1 Univ Pau & Pays Adour, CNRS, LCABIE, UMR 525, F-64053 Pau, France. Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Woods Hole, MA 02543 USA. Ctr Brest, REM GM, IFREMER, Plouzane, France. Univ Toulouse 3, CNRS, Georesources & Environm Toulouse GET, UMR 5563, F-31400 Toulouse, France. Ural Branch RAS, Inst Ecol Problems North, Arkhangelsk, Russia. Tomsk State Univ, BIO GEO CLIM Lab, Tomsk 634050, Russia. Univ Vermont, Dept Geol, Burlington, VT 05405 USA. Woods Hole Res Ctr, Falmouth, MA 02540 USA. Univ Cologne, Inst Geol & Mineral, D-50674 Cologne, Germany. C2 UNIV PAU & PAYS ADOUR, FRANCE WHOI, USA IFREMER, FRANCE UNIV TOULOUSE, FRANCE URAL BRANCH RAS, RUSSIA TOMSK STATE UNIV, RUSSIA UNIV VERMONT, USA WHOI, USA UNIV COLOGNE, GERMANY SI BREST SE PDG-REM-GM-LCG IN WOS Ifremer jusqu'en 2018 copubli-france copubli-europe copubli-univ-france copubli-int-hors-europe IF 1.61 TC 33 UR https://archimer.ifremer.fr/doc/00273/38402/36865.pdf LA English DT Article DE ;Iron isotope;Colloids;River;Weathering;Arctic;Iron speciation AB The input of iron to the Arctic Ocean plays a critical role in the productivity of aquatic ecosystems and is potentially impacted by climate change. We examine Fe isotope systematics of dissolved and colloidal Fe from several Arctic and sub-Arctic rivers in northern Eurasia and Alaska. We demonstrate that the Fe isotopic (δ56Fe) composition of large rivers, such as the Ob’ and Lena, has a restricted range of δ56Fe values ca.–0.11 ± 0.13‰, with minimal seasonal variability, in stark contrast to smaller organic-rich rivers with an overall δ56Fe range from–1.7 to + 1.6‰. The preferential enrichment with heavy Fe isotopes observed in low molecular weight colloidal fraction and during the high-flow period is consistent with the role of organic complexation of Fe. The light Fe isotope signatures of smaller rivers and meltwater reflect active redox cycling. Data synthesis reveals that small organic-rich rivers and meltwater in Arctic environments may contribute disproportionately to the input of labile Fe in the Arctic Ocean, while bearing contrasting Fe isotope compositions compared to larger rivers. PY 2015 PD NOV SO Comptes Rendus Geoscience SN 1631-0713 PU Elsevier France-editions Scientifiques Medicales Elsevier VL 347 IS 7-8 UT 000368867300008 BP 377 EP 385 DI 10.1016/j.crte.2015.04.005 ID 38402 ER EF