Sea-level and summer season orbital insolation as drivers of Arctic\n sea-ice

The sea-ice cover of the Arctic Ocean is an important element of the climate\nand ocean system in the Northern Hemisphere as it impacts albedo, atmospheric\npressure regimes, CO2-exchange at the ocean/atmosphere interface as well as the\nNorth Atlantic freshwater budget and thermohaline circulation [1]. Due to\nglobal warming, the Arctic sea-ice cover is presently evolving at an\nunprecedent rate towards full melt during the summer season, driving the\nso-called "Arctic amplification" [2]. However, the Arctic sea-ice has also\nexperienced large amplitude variations, from seasonal to orbital (Milankovitch)\ntime scales, in the past. Recent studies led to suggest that whereas insolation\nhas been a major driver of Arctic sea-ice variability through time, sea-level\nchanges governed the development of "sea-ice factories" over shelves (Figure\n1), thus fine-tuning the response of the Arctic Ocean to glacial/interglacial\noscillations that is slightly out of phase compared to lower latitudes [3,4].\nWe discuss below how insolation and sea-level changes may have interacted and\ncontrolled the sea-ice cover of the Arctic Ocean during warm past intervals and\nhow they could still interfere in the future.\n