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

TL;DR

This paper explores how past and present variations in insolation and sea-level influence Arctic sea-ice, highlighting their roles in climate dynamics and potential future interactions amid ongoing warming.

Contribution

It analyzes the combined effects of insolation and sea-level changes on Arctic sea-ice variability across different time scales, including recent and orbital periods.

Findings

Insolation has historically driven Arctic sea-ice variability.

Sea-level changes influenced the development of sea-ice factories.

Interactions between insolation and sea-level have modulated sea-ice response over time.

Abstract

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