Anomalous collapses of Nares Strait ice arches leads to enhanced export of Arctic sea ice

TLDR

Ice arches at the ends of Nares Strait regulate the export of multi‑year Arctic sea ice, a process that is increasingly important as the Arctic ice pack becomes younger, thinner, and more mobile. The study reports on recent behavior of Nares Strait ice arches and their ice fluxes using Sentinel‑1 sea‑ice motion retrievals. We analyze Sentinel‑1 derived sea‑ice motion to quantify arch formation and ice fluxes along Nares Strait. Arch formation duration has shortened over the past two decades, while ice area and volume fluxes have risen, indicating a shift toward atypical arch formation and accelerated export of multi‑year ice, hastening the Arctic’s transition to a younger, thinner ice pack.

Abstract

Abstract The ice arches that usually develop at the northern and southern ends of Nares Strait play an important role in modulating the export of Arctic Ocean multi-year sea ice. The Arctic Ocean is evolving towards an ice pack that is younger, thinner, and more mobile and the fate of its multi-year ice is becoming of increasing interest. Here, we use sea ice motion retrievals from Sentinel-1 imagery to report on the recent behavior of these ice arches and the associated ice fluxes. We show that the duration of arch formation has decreased over the past 20 years, while the ice area and volume fluxes along Nares Strait have both increased. These results suggest that a transition is underway towards a state where the formation of these arches will become atypical with a concomitant increase in the export of multi-year ice accelerating the transition towards a younger and thinner Arctic ice pack.