The Transpolar Drift conveys methane from the Siberian Shelf to the central Arctic Ocean.

Autor:	Damm E; Alfred Wegener Institute Helmholtz-Centre for Polar and Marine Research P.O. Box 12061, 27515, Bremerhaven, Germany. Ellen.Damm@awi.de., Bauch D; GEOMAR Helmholtz-Centre for Ocean Research, Wischhofstrasse1-3, 24148, Kiel, Germany., Krumpen T; Alfred Wegener Institute Helmholtz-Centre for Polar and Marine Research P.O. Box 12061, 27515, Bremerhaven, Germany., Rabe B; Alfred Wegener Institute Helmholtz-Centre for Polar and Marine Research P.O. Box 12061, 27515, Bremerhaven, Germany., Korhonen M; Finnish Meteorological Institute, Erik Palmenin aukio 1 P.O. Box 503, FI-00101, Helsinki, Finland., Vinogradova E; Shirshov Institute of Oceanology, Russian Academy of Science, 36, Nahimovskiy prospekt, 117997, Moscow, Russia., Uhlig C; Alfred Wegener Institute Helmholtz-Centre for Polar and Marine Research P.O. Box 12061, 27515, Bremerhaven, Germany.
Jazyk:	angličtina
Zdroj:	Scientific reports [Sci Rep] 2018 Mar 14; Vol. 8 (1), pp. 4515. Date of Electronic Publication: 2018 Mar 14.
DOI:	10.1038/s41598-018-22801-z
Abstrakt:	Methane sources and sinks in the Arctic are poorly quantified. In particular, methane emissions from the Arctic Ocean and the potential sink capacity are still under debate. In this context sea ice impact on and the intense cycling of methane between sea ice and Polar surface water (PSW) becomes pivotal. We report on methane super- and under-saturation in PSW in the Eurasian Basin (EB), strongly linked to sea ice-ocean interactions. In the southern EB under-saturation in PSW is caused by both inflow of warm Atlantic water and short-time contact with sea ice. By comparison in the northern EB long-time sea ice-PSW contact triggered by freezing and melting events induces a methane excess. We reveal the Ttranspolar Drift Stream as crucial for methane transport and show that inter-annual shifts in sea ice drift patterns generate inter-annually patchy methane excess in PSW. Using backward trajectories combined with δ 18 O signatures of sea ice cores we determine the sea ice source regions to be in the Laptev Sea Polynyas and the off shelf regime in 2011 and 2015, respectively. We denote the Transpolar Drift regime as decisive for the fate of methane released on the Siberian shelves.
Databáze:	MEDLINE
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