Figure 4

(A) Time evolution of the ice flux at the grounding-line along the Bjørnøyrenna Ice Stream cross section AB shown in Fig. 1 in GBvol (red line) and PBvol (blue line) simulations. When the ice flux at the grounding-line approaches zero, the Bjørnøyrenna Ice Stream can be considered as fully retreated. The Bjørnøyrenna Ice Stream retreat history according to geological data^4,5,6 is summarized at the top of the plot. Red/blue shades highlight periods of warm/cold annual mean ocean temperature (400 m depth) and high/low global sea level prescribed in the ISM simulations. (B) Indexes for the annual mean ocean temperature in the South-western Barents Sea at 400 m depth (dark blue line) used to interpolate between LGM and PI ocean conditions and for the regional sea level (dark yellow line). The ocean temperature index is based on the Trace-21ka fully coupled transient simulation²², whereas the regional sea level index is based on the NGRIP δ 18 O record²⁹. Red/blue shades highlight periods of warm/cold annual mean ocean temperature (400 m depth) and high/low global sea level prescribed in the ISM simulations.