A Lagrangian Analysis of the Dynamical and Thermodynamic Drivers of Greenland Warm Events during 1979-2017 ...

• Main Author: Hermann, Mauro
• Format: Text
• Language: English
• Published: ETH Zurich 2019
• Subjects: atmospheric dynamics; Greenland; warm events; ERA-Interim; backward trajectories; infoeu-repo/classification/ddc/500; Natural sciences; FOS Natural sciences; Ice Sheet; North Atlantic
• Online Access: https://dx.doi.org/10.3929/ethz-b-000348060; http://hdl.handle.net/20.500.11850/348060

The acceleration of mass loss from the Greenland Ice Sheet (GrIS) since the late 1990s was primarily driven by increased surface melt, partly concentrated in single extreme melt events. A textbook example was observed around 12 July 2012 (EV69), when almost the entire GrIS was melting, including Summit Station at 3216 m in the dry inland plateau. The melt event coincided with strong meridional air mass transport towards the GrIS followed by a Greenland blocking, which resembles the anomalous synoptic pattern that became increasingly frequent in the North Atlantic region in the last two decades. Here, we investigate the atmospheric forcing of extraordinary melt periods by assessing the main dynamical and thermodynamic processes that cause so-called warm events. We present an ERA-Interim-based climatology of 77 Greenland warm events affecting the high accumulation area in 1979-2017. These events became longer and more frequent during the study period. With Lagrangian backward trajectories started from the ...