Fig 1.
The model domain of the ice sheet model.
The model domain of the ice sheet model. The left subpanel shows the ice thickness used to initialise the model (shading) and the contemporary coast line (black contour line) while the right subpanel depicts the corresponding bedrock topography. These data are derived from the ETOPO1 data set [42].
Table 1.
List of ensemble simulations in this study.
Fig 2.
The AWI-ESM prescribed summer (June-July-August: JJA) 2m-air temperature in different periods (plotted as anomaly to the Pre-Industrial conditions).
The absolute 2m-air temperature at the Pre-Industrial era is presented in the bottom panel. The contemporary coast line is highlighted in the black line (see Fig 1 for details). The grey contours give the ice sheet geometry used in the climate model.
Fig 3.
Same as Fig 2, but for annual mean precipitation.
Fig 4.
The evolution of Greenland’s climate and simulated ice volume of the GrIS from the last interglacial to the Pre-Industrial era.
(A): The prescribed forcing of summer (JJA) atmospheric temperature (red line), yearly mean ocean temperature (blue line) and global mean sea level (black line). (B): The simulated ice volume evolution of the GrIS. The coloured lines are the results from individual ensemble members (see Table 1). The thick black line gives the ensemble mean values. The red shadow area marks the time period when Greenland’s climate gets warmer, and the blue patch illustrates the time when Greenland’s climate colds.
Fig 5.
Evolution of Greenland Ice Sheet from the Holocene Thermal Maximum (i.e., 8 ka) to the Pre-Industrial era.
A, top: Blue line: the oxygen δ 18O isotope record from the NGRIP ice core [62]. Red line: the prescribed forcing of summer (JJA) temperature. Black line: July insolation at 70°N [78]. B, center: Black line: ice volume of the GrIS. Pink line: total ice area of the GrIS. Blue line: floating ice area. C, bottom: Black line: surface mass balance of the GrIS. Blue line: total mass balance, positive indicate mass gain, and vice versa. Red line: rate of dynamic ice loss, i.e., discharge ice flux. As the sub-shelf ice flux and grounded basal mass flux are one order of magnitude smaller than that of the surface mass balance and the dynamic ice loss, the total mass balance of the GrIS is primarily controlled by the surface mass balance and dynamic ice loss. The above results are all based on the ensemble mean of the seven ensemble simulations.
Fig 6.
The evolution of Greenland’s climate and ice volume during 1850–2100.
(A): Black line: concentration of CO2 forcing in our climate model simulation. Blue line: yearly mean ocean temperature forcing. Red line: Greenland-wide summer temperature anomalies in respect to the Pre-Industrial values (100 years of climatology mean). (B): Anomaly of ice volume of the GrIS with respect to the Pre-Industrial values. The solid lines are the simulations using initial conditions obtained by the paleo-spinup, while the dashed lines are the results using initial conditions obtained by a ten thousand year Pre-Industrial equilibrium-spinup. The coloured lines are the results from individual ensemble members (see Table 1), and the thick black lines are the results of the ensemble mean.
Fig 7.
The simulated evolution of the (A, top) ice volume, (B, center) ice temperature (average over entire GrIS) and (C, bottom) dynamic ice loss in the paleo-spinup (solid lines) and the equilibrium-spinup (dashed lines).
All results are given as anomalies with respect to the corresponding Pre-Industrial (i.e., 1850) values. The coloured lines are results from individual ensemble members, and the thick black lines are the ensemble mean.
Fig 8.
(A, left) Ice thickness and (B, right) surface ice velocity anomaly between the initial conditions obtained from the equilibrium-spinup and paleo-spinup (equilibrium minus paleo).
Black line represents the coastline. As shown, individual glaciers have distinct responses. Overall, northeastern Greenland contributes to a larger GrIS ice volume in comparison with the that obtained from the paleo-spinup. With respect to the surface ice velocity, large portions of the GrIS show faster ice velocity in the equilibrium-spinup with respect to that obtained from paleo-spinup. Results are the ensemble mean of the seven ensemble members.