Impacts of early-winter Arctic sea-ice loss on wintertime surface temperature in China

• Published in: Climate dynamics 2024-07, Vol.62 (7), p.6579-6597
• Main Authors: Xia, Xufan, Zhang, Jiankai, Xu, Mian, Zhang, Chongyang, Song, Jibin, Wei, Dong, Liu, Liwei
• Format: Article
• Language: English
• Subjects: Ablation; Air temperature; Anomalies; Arctic sea ice; Climate change; Climatology; Cold days; Cooling; Dynamic height; Earth and Environmental Science; Earth Sciences; Extreme cold; Extreme low temperatures; Extreme values; Extreme weather; Geophysics/Geodesy; Geopotential; Geopotential height; Global warming; Height anomalies; Ice; Impact analysis; Linkage analysis; Low temperature; Northern Hemisphere; Oceanography; Original Article; Planetary waves; Polar vortex; Sea ice; Stratosphere; Stratospheric polar vortexes; Stratospheric vortices; Surface cooling; Surface temperature; Surface-air temperature relationships; Troposphere; Wave packets; Wave propagation; Wave trains; Weather; Winter; Winter weather
• ISSN: 0930-7575; 1432-0894
• DOI: 10.1007/s00382-024-07225-y

Under the background of global warming, the impact of Arctic sea-ice loss on mid-latitude weather and climate in the Northern Hemisphere has attracted widespread attention. Here, using both observations and model simulations, the influence of early-winter Barents-Kara Seas (BKS) sea-ice loss on the winter surface air temperatures in China and the underlying mechanisms are investigated. The results showed that BKS sea-ice loss could induce cooling anomalies over Northeast China, North China, Central China, and Northwest China during winter, with significant increases in both the number of extreme cold days and the intensity of extreme low temperatures over these regions. Furthermore, the respective roles of tropospheric pathway and stratospheric pathway are investigated. For the tropospheric pathway, an eastward propagating wave train stimulated by sea-ice loss induces negative geopotential height anomalies over the western Pacific, favorable for the transport of cold airmass into China. In terms of the stratospheric pathway, sea-ice loss leads to the extension of stratospheric polar vortex edge toward North China by modulating upward propagating planetary waves, further enhancing the tropospheric cooling there. The quantitative analysis indicates that the impact of stratospheric pathway on surface cooling over Northeast China associated with BKS sea-ice loss is more important than that over other regions in China. These results could improve our understanding of the potential linkage between Arctic sea-ice loss and winter weather extremes over China.