Arctic Heatwaves on the Rise: New Study Uncovers Link Between Autumn Warm Spells and Sea Ice Decline in Barents-Kara Sea 

Amid global warming, heatwaves are striking even the Arctic, a region once considered immune to such extreme weather events. Recent research reveals that these heatwaves, particularly in the Barents-Kara Sea (BKS) during the boreal autumn, are not only increasing in frequency but are also impacting the climate far beyond the Arctic, including East Asia and globally. 

A study published in Weather and Climate Extremes delves into the mechanism of these autumn heatwaves in the BKS and their connection to sea ice variability. Researchers found that two days before these heatwaves occur, a distinct atmospheric pattern emerges: a dipole mode featuring a negative anomaly over Greenland and a positive anomaly over the BKS. 

“This dipole mode facilitates the continuous inflow of warm, moist air from the Atlantic into the BKS region,” explains Dr. HU Wenting, the study’s corresponding author and a researcher with the Institute of Atmospheric Physics at the Chinese Academy of Sciences. The influx of warmth and moisture intensifies downward longwave radiation, as well as latent and sensible heat fluxes, driving up near-surface air temperatures and triggering these compound heatwaves. 

The study also highlights that this increase in warmth and moisture drastically reduces sea ice concentration in the BKS region. This sea ice decline continues until at least one day after the heatwave, suggesting a feedback loop where higher temperatures may prolong the heatwave’s impact.

These findings underscore the critical role of sea ice in regulating Arctic temperatures and hint at broader implications for global climate patterns as Arctic conditions continue to change. 

Reference: Xin, Y., Hu, W., Duan, A., Tang, B., & Tang, Y. (2024). Mechanism for compound daytime-nighttime heatwaves in the Barents–Kara Sea during the boreal autumn and their relationship with sea ice variability. Weather and Climate Extremes, 100712. Paper link: https://doi.org/10.1016/j.wace.2024.100712

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