Table 1 Atmosphere-ocean forcing combinations applied to the ice sheet model.

The top row and the leftmost column, respectively, refer to the six atmosphere forcings and the six ocean forcings applied to the ice sheet model. In total, 36 simulations of the ensemble are performed, with each table entry referring to an individual simulation. The atmosphere forcing is applied in the form of surface air temperature (SAT), precipitation (7.0%/°C), and sea ice resistance anomalies to a regional climatology from the TraCE-21ka and LOVECLIM transient climate simulations, the EDC and WDC ice core records, and an MPA of each atmosphere forcing. The ocean forcing is applied in the form of subshelf mass flux (melt rate) offsets based on the climate model simulations, two benthic ocean temperature (OT) reconstructions, and an MPA (LOVECLIM 400m T and two benthic OT reconstructions). We define three scenarios, namely, warm, moderate, and cool, based on LGM SAT anomalies and timing and amount of early deglacial ocean warming (Figs. 1 and 2). SST, sea surface temperature.

LOVECLIM-1 SAT (full
domain)
“Warm atmosphere”
WDC SATMPA SAT
“Moderate atmosphere”
EDC SATLOVECLIM-2 SAT2
(coastal region only)
TraCE-21ka SAT
“Cool atmosphere”
LOVECLIM 400m ocean T
“Warm ocean”
LOVECLIM SAT,
LOVECLIM 400m T
“Warm scenario”
WDC SAT,
LOVECLIM 400m T
MPA SAT, LOVECLIM
400m T
EDC SAT,
LOVECLIM 400m T
LOVECLIM SAT2,
LOVECLIM 400m T
TraCE SAT,
LOVECLIM 400m T
TraCE-21ka 400m ocean TLOVECLIM SAT, TraCE
400m T
WDC SAT, TraCE
400m T
MPA SAT, TraCE
400m T
EDC SAT, TraCE
400m T
LOVECLIM SAT2, TraCE
400m T
TraCE SAT, TraCE
400m T
MPA ocean T
“Moderate ocean”
LOVECLIM SAT, MPA
OT
WDC SAT, MPA OTMPA SAT, MPA OT
“Moderate
scenario”
EDC SAT, MPA OTLOVECLIM SAT2, MPA
OT
TraCE SAT, MPA OT
Southern Ocean benthic ocean T
(SOT) reconstruction (20)
LOVECLIM SAT, SOTWDC SAT, SOTMPA SAT, SOTEDC SAT, SOTLOVECLIM SAT2, SOTTraCE SAT, SOT
Global benthic ocean T (GOT)
reconstruction (19)
LOVECLIM SAT, GOTWDC SAT, GOTMPA SAT, GOTEDC SAT, GOTLOVECLIM SAT2, GOTTraCE SAT, GOT
TraCE-21ka SST
“Cool ocean”
LOVECLIM SAT, TraCE
SST
WDC SAT, TraCE
SST
MPA SAT, TraCE SSTEDC SAT, TraCE
SST
LOVECLIM SAT2, TraCE
SST
TraCE SAT, TraCE SST
“Cool scenario”