Role of atmospheric rivers in shaping long term Arctic moisture variability

• Published in: Nature Communications
• Main Authors: Zhibiao Wang, Qinghua Ding, Renguang Wu, Thomas J. Ballinger, Bin Guan, Deniz Bozkurt, Deanna Nash, Ian Baxter, Dániel Topál, Zhe Li, Gang Huang, Wen Chen, Shangfeng Chen, Xi Cao, Zhang Chen
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Portfolio 2024
• Subjects: Science; Q; Greenland; Siberia
• Online Access: https://doi.org/10.1038/s41467-024-49857-y; https://doaj.org/article/836b26f9c47c45ac9ac6ee5d971dc41a

Abstract Atmospheric rivers (ARs) reaching high-latitudes in summer contribute to the majority of climatological poleward water vapor transport into the Arctic. This transport has exhibited long term changes over the past decades, which cannot be entirely explained by anthropogenic forcing according to ensemble model responses. Here, through observational analyses and model experiments in which winds are adjusted to match observations, we demonstrate that low-frequency, large-scale circulation changes in the Arctic play a decisive role in regulating AR activity and thus inducing the recent upsurge of this activity in the region. It is estimated that the trend in summertime AR activity may contribute to 36% of the increasing trend of atmospheric summer moisture over the entire Arctic since 1979 and account for over half of the humidity trends in certain areas experiencing significant recent warming, such as western Greenland, northern Europe, and eastern Siberia. This indicates that AR activity, mostly driven by strong synoptic weather systems often regarded as stochastic, may serve as a vital mechanism in regulating long term moisture variability in the Arctic.