Anomalous Circulation in July 2019 Resulting in Mass Loss on the Greenland Ice Sheet. Issue 17 (7th September 2020)

• Record Type: Journal Article
• Authors: Cullather, Richard I.; Andrews, Lauren C.; Croteau, Michael J.; Digirolamo, Nicolo E.; Hall, Dorothy K.; Lim, Young‐Kwon; Loomis, Bryant D.; Shuman, Christopher A.; Nowicki, Sophie M. J.
• Is Part Of: Geophysical research letters. Volume 47:Issue 17(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-09-07
• Subjects: melt event -- Greenland Ice Sheet -- mass loss -- jet stream; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2020GL087263
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Current mass loss on the Greenland Ice Sheet (GrIS) includes a significant contribution from surface runoff. The circumstances associated with melt events are important for understanding the global sea level contribution of the GrIS. In late July 2019, surface melt occurred over 62% of the GrIS, including Summit Station. The general circulation leading to the event is found to be dissimilar to 2012 and other events documented in the 21st century, with warm air associated with remote atmospheric blocking over western Europe eventually transiting west to the GrIS. Gravimetric data indicate that the 2019 summer mass loss was 137 Gt more than the 2004–2010 median, or about 92% of the 2012 record. Mass loss during the event was significant in GrIS northeastern regions in 2019. As compared to 2012, the southwest did not fully participate. Similar circulation patterns have not previously been associated with significant melt. Key Points: Extensive surface melt occurred on the Greenland Ice Sheet on 30–31 July 2019 that included Summit Station Unlike the 2012 record event, mass loss in the southwestern ice sheet was not as large, while losses in the northeast were comparable The melt patterns were driven by a westward advection of a warm air mass that differs from prior events