Arctic sea ice melt season stabilizes after decades of lengthening

A NASA-led study analyzing satellite observations from 1979 to 2023 has found that the Arctic sea ice melt season has unexpectedly stabilized since approximately 2010. While the melt season is currently about 40 days longer than it was in 1979, most of that expansion occurred prior to 2010.

Researchers determined that the lengthening of the melt season was primarily driven by sea ice freezing later in the autumn rather than melting earlier in the spring. Linette Boisvert, an ice researcher at NASA's Goddard Space Flight Center and study co-author, noted that the reduction in multi-year ice has resulted in thinner ice and increased variability.

Although the average length of the melt season has remained relatively steady since 2010, the region continues to experience significant year-to-year fluctuations. The study team examined the Arctic energy balance—the difference between incoming solar, atmospheric, and oceanic energy and the infrared energy escaping into space—to investigate the causes behind the shift in trends.