Increasing extreme melt in northeast Greenland linked to foehn winds and atmospheric rivers

• Published in: Nature communications Vol. 14; no. 1; p. 1743
• Main Authors: Mattingly, Kyle S., Turton, Jenny V., Wille, Jonathan D., Noël, Brice, Fettweis, Xavier, Rennermalm, Åsa K., Mote, Thomas L.
• Format: Journal Article Web Resource
• Language: English
• Published: London Nature Publishing Group UK 29.03.2023; Nature Publishing Group; Springer Science and Business Media LLC; Nature Portfolio
• Subjects: 704/106/125; 704/106/35/823; 704/106/694/1108; Atmospheric moisture; Climate change; Earth sciences & physical geography; Foehn; General Biochemistry, Genetics and Molecular Biology; General Chemistry; General Physics and Astronomy; Glaciers; Global warming; Humanities and Social Sciences; Ice sheets; Moisture content; Moisture effects; Multidisciplinary; Outlets; Physical, chemical, mathematical & earth Sciences; Physique, chimie, mathématiques & sciences de la terre; Science; Science (multidisciplinary); Sciences de la terre & géographie physique; Sea level rise; Water content; Water vapor; Greenland
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-37434-8

The Greenland Ice Sheet has been losing mass at an increased rate in recent decades. In northeast Greenland, increasing surface melt has accompanied speed-ups in the outlet glaciers of the Northeast Greenland Ice Stream, which contain over one meter of sea level rise potential. Here we show that the most intense northeast Greenland melt events are driven by atmospheric rivers (ARs) affecting northwest Greenland that induce foehn winds in the northeast. Near low-elevation outlet glaciers, 80–100% of extreme (> 99 th percentile) melt occurs during foehn conditions and 50–75% during ARs. These events have become more frequent during the twenty-first century, with 5–10% of total northeast Greenland melt in several recent summers occurring during the ~1% of times with strong AR and foehn conditions. We conclude that the combined AR-foehn influence on northeast Greenland extreme melt will likely continue to grow as regional atmospheric moisture content increases with climate warming. Extreme ice sheet melt events in northeast Greenland occur after intense water vapor transport into northwest Greenland by atmospheric rivers. Through the foehn effect, the air becomes warmer and drier as it descends the ice sheet slope.