Fig. 1: Petermann Ice Shelf-fjord system: Model domain, fjord hydrography, and discharge-driven mean response of melt and its drivers. | Nature Communications

Fig. 1: Petermann Ice Shelf-fjord system: Model domain, fjord hydrography, and discharge-driven mean response of melt and its drivers.

From: Enhanced subglacial discharge amplifies Petermann Ice Shelf melting when ocean thermal forcing saturates

Fig. 1

A map of our regional Petermann Ice Shelf and fjord model domain (a) (in a wider context shown in the inset in the upper left corner) overlaid on a shaded relief representation of the bathymetric grid from the International Bathymetric Chart of the Arctic Ocean v4.069. The mesh size in the model domain varies regionally, as exemplified by the three green-framed boxes. Open ocean boundaries in the Lincoln Sea and Baffin Bay are marked with red lines. Petermann Fjord is surrounded by a purple polygon, detailed in panel (b). b Petermann Ice Shelf extent (white outline), from CE 2009, overlaid on water column thickness (WCT) in Petermann Fjord and adjacent parts of Nares Strait. The cyan line marks the grounding line, where discharge (detailed in panel (c)) is injected into the model. The red line marks the location of the transect over which the temperature, salinity, and flow along the fjord are investigated. The magenta star denotes the node ca. 10 km from the grounding line at which the vertical profile of temperature and salinity are shown. Blue and yellow lines, respectively, represent the transects across which overturning circulation and diagnostics for meltwater convergence are shown. c Discharge (Qsg) scenarios, 1950–2100 CE, obtained by forcing the Modéle Atmosphérique Régional with five general circulation models43,65. Shaded vertical stripes with blue and red stippled outlines denote the periods over which Qsg-present (CE 1995–2014) and Qsg-RCP 8.5 (CE 2081–2100), respectively, are averaged over (Table 1). Blue, magenta, and red horizontal stippled lines correspond to Qsg-present (372 m3/s), Qsg-median (1563 m3/s), and Qsg-RCP 8.5 (2754 m3/s) discharge magnitudes, respectively. d A graphical summary of the results showing basal melt rate (mb), and its drivers, namely, thermal driving (ΔT) and friction velocity (u*). The discharge type categories correspond to the experiment design (Table 1).

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