Figure 1
From: The Transpolar Drift conveys methane from the Siberian Shelf to the central Arctic Ocean
(a) Transpolar Drift Stream (TDS), Polar surface water (PSW) and Atlantic water (AW) circulation pattern in the Eurasian Basin (EB). (b) Temperature vs. salinity in PSW; grey arrows show increasing saturation concentration of methane (calculated). (c) Methane saturation concentration vs. methane saturation separated in a cooling and freshening branches. (a) The PSW in the southern EB is influenced by inflowing AW (blue arrows) from SW and by the TDS (white arrows) flowing in the opposite direction i.e. from NE. (b) Cooling-down is evident in the AW-influenced PSW (blue crosses) in the southern EB. In comparison, freshening by sea ice melt is most apparent in TDS-influenced PSW in the northern EB (green dots and red circles). Two separate branches of increasing methane saturation concentrations are related to cooling and freshening (grey arrows). (c) Saturation concentration vs. saturation reveals methane under-saturated to slightly super-saturated PSW in the southern EB along the cooling branch (blue crosses) and large differences in supersaturation from the cooling to the freshening branch in the northern EB between 2011 (red circles) and 2015 (green dots). Map and plots are generated with MATLAB 2013b.
