Impact of millennial-scale oceanic variability on the Greenland ice sheet evolution throughout the Last Glacial Period

Ilaria Tabone, Alexander Robinson, Jorge Alvarez-Solas, Marisa Montoya
2018 Climate of the Past Discussions  
<p><strong>Abstract.</strong> Temperature reconstructions from Greenland ice sheet (GrIS) ice cores indicate the occurrence of more than twenty abrupt warmings during the Last Glacial Period (LGP) known as Dansgaard-Oeschger (D-O) events. Although their ultimate cause is still debated, evidence from both proxy data and modelling studies robustly links these to reorganisations of the Atlantic Meridional Overturning Circulation (AMOC). During the LGP, the GrIS expanded as far as the continental
more » ... s the continental shelf break and was thus more directly exposed to oceanic changes than in the present. Therefore oceanic temperature fluctuations on millennial timescales could have had a non-negligible impact on the GrIS. Here we assess the effect of millennial-scale oceanic variability on the GrIS evolution from the last interglacial to the present day. To do so, we use a three-dimensional hybrid ice-sheet-shelf model forced by oceanic fluctuations derived from paleo records. We show that the GrIS evolution during the LGP could have been strongly influenced by oceanic changes on millennial timescales, leading to ocean-induced ice volume contributions more than 1.5&amp;thinsp;m SLE. Several regions across the GrIS could thus have been responsible for ice mass discharge during D-O events, opening the possibility of a non-negligible role of the GrIS in oceanic reorganisations throughout the LGP.</p>
doi:10.5194/cp-2018-129 fatcat:3algzld335a7lgvasswopyayt4