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Changing surface–atmosphere energy exchange and refreezing capacity of the lower accumulation area, West Greenland
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-18)
We present 5 years (2009–2013) of automatic weather station measurements from the lower accumulation area (1840 m a.s.l. – above sea level) of the Greenland ice sheet in the Kangerlussuaq region. Here, the summers of 2010 and 2012 were both exceptionally warm, but only 2012 resulted in a strongly negative surface mass budget (SMB) and surface meltwater run-off. The observed run-off was ...
UAV photogrammetry and structure from motion to assess calving dynamics at Store Glacier, a large outlet draining the Greenland ice sheet
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-01-06)
This study presents the application of a costeffective, unmanned aerial vehicle (UAV) to investigate calving dynamics at a major marine-terminating outlet glacier draining the western sector of the Greenland ice sheet. The UAV was flown over Store Glacier on three sorties during summer 2013 and acquired over 2000 overlapping, geotagged images of the calving front at an ∼ 40 cm ground sampling ...
Biocryomorphology: integrating microbial processes with ice surface hydrology, topography and roughness
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-12-02)
Geophysical constraints on the dynamics and retreat of the Barents Sea ice sheet as a palaeobenchmark for models of marine icesheet deglaciation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-14)
Our understanding of processes relating to the retreat of marine-based ice sheets, such as the West Antarctic Ice Sheet and tidewater-terminating glaciers in Greenland today, is still limited. In particular, the role of ice-stream instabilities and oceanographic dynamics in driving their collapse are poorly constrained beyond observational timescales. Over numerous glaciations during the Quaternary, ...
Extraordinary runoff from the Greenland ice sheet in 2012 amplified by hypsometry and depleted firn retention
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-05-30)
It has been argued that the infiltration and retention of meltwater within firn across the percolation zone of the Greenland ice sheet has the potential to buffer up to ∼ 3.6 mm of global sea-level rise (Harper et al., 2012). Despite evidence confirming active refreezing processes above the equilibrium line, their impact on runoff and proglacial discharge has yet to be assessed. Here, we compare ...
Deglaciation of the Eurasian ice sheet complex
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-14)
The Eurasian ice sheet complex (EISC) was the third largest ice mass during the Last Glacial Maximum with a span of over 4500 km and responsible for around 20 m of eustatic sea-level lowering. Whilst recent terrestrial and marine empirical insights have improved understanding of the chronology, pattern and rates of retreat of this vast ice sheet, a concerted attempt to model the deglaciation of the ...
Physical Conditions of Fast Glacier Flow: 2. Variable Extent of Anisotropic Ice and Soft Basal Sediment From Seismic Reflection Data Acquired on Store Glacier, West Greenland
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-09)
Outlet glaciers of the Greenland Ice Sheet transport ice from the interior to the ocean and contribute directly to sea level rise because discharge and ablation often exceed the accumulation. To develop a better understanding of these fast‐flowing glaciers, we investigate the basal conditions of Store Glacier, a large outlet glacier flowing into Uummannaq Fjord in west Greenland. We use two crossing ...
Dark zone of the Greenland Ice Sheet controlled by distributed biologically-active impurities
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-03-14)
Albedo—a primary control on surface melt—varies considerably across the Greenland Ice Sheet yet the specific surface types that comprise its dark zone remain unquantified. Here we use UAV imagery to attribute seven distinct surface types to observed albedo along a 25 km transect dissecting the western, ablating sector of the ice sheet. Our results demonstrate that distributed surface impurities—an ...
Supraglacial ponds regulate runoff from Himalayan debris-covered glaciers
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-29)
Meltwater and runoff from glaciers in High Mountain Asia is a vital freshwater resource for one-fifth of the Earth’s population. Between 13% and 36% of the region’s glacierized areas exhibit surface debris cover and associated supraglacial ponds whose hydrological buffering roles remain unconstrained. We present a high-resolution meltwater hydrograph from the extensively debris-covered Khumbu ...
Glacial isostatic adjustment associated with the Barents Sea ice sheet: A modelling inter-comparison
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-09-01)
The 3D geometrical evolution of the Barents Sea Ice Sheet (BSIS), particularly during its late-glacial retreat phase, remains largely ambiguous due to the paucity of direct marine- and terrestrial-based evidence constraining its horizontal and vertical extent and chronology. One way of validating the numerous BSIS reconstructions previously proposed is to collate and apply them under a wide range ...