Work

Recent slowing of Arctic sea ice melt tied to multidecadal NAO variability

Year: 2025

Type: article

Abstract: The reduction of Arctic sea ice concentration (SIC) is a key indicator of global warming. In September 2012, SIC reached its lowest recorded value. Since then, sea ice melt has slowed down, showing a linear trend of only −0.4±6.8%/decade from 2012 to 2023, compared to −11.3±3.3%/decade from 1996 to 2011. Here, we demonstrate that the recent slowdown in September sea ice melt is closely coupled with the multi-decadal variability of the preceding summer North Atlantic Oscillation (NAO), which has transitioned from the lowest point of its negative phase in the early 2010s to a positive phase. During this shift, decreased heat and moisture, along with reduced downward longwave radiation, have contributed to offsetting the long-term decline, leading to a slowdown in Arctic sea ice melting. Additionally, the Atlantic Multidecadal Oscillation plays a primary role in driving the interdecadal variability of the NAO and Arctic sea ice by modulating wave-mean flow interactions. This study shows that the slowdown in September Arctic sea ice loss is linked to the shift towards a positive phase of the North Atlantic Oscillation, which reduces heat and moisture transport and longwave radiation, partially offsetting the long-term decline of Arctic sea ice.

Source: Nature Communications

DOI: 10.1038/s41467-025-63520-0