Oceanic heat delivery via Kangerdlugssuaq Fjord to the south-east Greenland ice sheet

Acceleration of the Greenland Ice Sheet (GrIS) tidewater outlet glaciers has increased the ice sheet's contribution to global sea level rise over the last two decades. Coincident increases in atmospheric temperatures around Greenland explain some of the increased ice loss, but warm Atlantic-ori...

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Bibliographic Details
Published in:Journal of Geophysical Research: Oceans
Main Authors: Inall, Mark, Murray, Tavi, Cottier, Finlo, Scharrer, Kilian, Boyd, Tim, Heywood, K J, Bevan, Suzanne
Format: Article in Journal/Newspaper
Language:English
Published: 2014
Subjects:
Online Access:https://pure.uhi.ac.uk/en/publications/0f4981be-bb07-4acd-9259-14491963bd77
https://doi.org/10.1002/2013JC009295
https://pureadmin.uhi.ac.uk/ws/files/2429148/Inall_et_al_2014_Journal_of_Geophysical_Research_Oceans.pdf
Description
Summary:Acceleration of the Greenland Ice Sheet (GrIS) tidewater outlet glaciers has increased the ice sheet's contribution to global sea level rise over the last two decades. Coincident increases in atmospheric temperatures around Greenland explain some of the increased ice loss, but warm Atlantic-origin water (AW) is increasingly recognized as contributing to the accelerating ice-mass loss, particularly, via the outlet glaciers of south-east (SE) Greenland. However, there remains a lack of understanding of the variability in heat content of the water masses found to the east of Greenland and how this heat is communicated to the outlet glaciers of the GrIS. Here a new analysis is presented of ocean/GrIS interaction in which the oceanic heat flux toward the ice sheet in Kangerdlugssuaq Fjord (0.26 TW) is an order-of-magnitude greater than that reported for the other major outlet glacier of SE Greenland (Helheim). Heat delivered by AW to the calving front of Kangerdlugssuaq is equivalent to 10 m d21 melt (i.e., 30¿60% of the ice flow speed), and thus is highly significant. During the observational campaign in September 2010 warm Polar Surface Water (PSWw) melted a substantial volume of ice within the fjord; equivalent to 25% of the volume melted by AW alone. Satellite-derived sea surface temperatures show large interannual variability in PSWw over the 20 year period 1991¿2011. Anomalously warm PSWw was observed within the fjord prior to the welldocumented major ice front retreats of May 2004 and November 2010.