Blar i forfatter "Box, J.E."

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    • Changing surface–atmosphere energy exchange and refreezing capacity of the lower accumulation area, West Greenland 

      Charalampidis, C.; Van As, D.; Box, J.E.; van den Broeke, M.R.; Colgan, W.T.; Doyle, S.H.; Hubbard, Alun Lloyd; MacFerrin, M.; Machguth, H.; Smeets, C.J.P.P. (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 ...

    • How robust are in situ observations for validating satellite-derived albedo over the dark zone of the Greenland Ice Sheet? 

      Ryan, J.C.; Hubbard, Alun Lloyd; Irvine-Fynn, T.; Doyle, S.H.; Cook, J.M.; Stibal, Marek; Box, J.E. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-17)
      Calibration and validation of satellite‐derived ice sheet albedo data require high‐quality, in situ measurements commonly acquired by up and down facing pyranometers mounted on automated weather stations (AWS). However, direct comparison between ground and satellite‐derived albedo can only be justified when the measured surface is homogeneous at the length‐scale of both satellite pixel and in situ ...

    • Physical Conditions of Fast Glacier Flow: 1. Measurements From Boreholes Drilled to the Bed of Store Glacier, West Greenland 

      Doyle, S. H.; Hubbard, B.; Christoffersen, P.; Young, T.J.; Hofstede, C; Bougamont, M.; Box, J.E.; Hubbard, A.L. (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-21)
      Marine‐terminating outlet glaciers of the Greenland Ice Sheet make significant contributions to global sea level rise, yet the conditions that facilitate their fast flow remain poorly constrained owing to a paucity of data. We drilled and instrumented seven boreholes on Store Glacier, Greenland, to monitor subglacial water pressure, temperature, electrical conductivity, and turbidity along with ...

    • Storage and export of microbial biomass across the western Greenland Ice Sheet 

      Irvine-Fynn, Tristram D.L.; Edwards, A.; Stevens, I.T.; Mitchell, A.C.; Bunting, P.; Box, J.E.; Cameron, K.A.; Cook, J.M.; Naegeli, K.; Rassner, S.M.E.; Ryan, J.C.; Stibal, M.; Williamson, C.J.; Hubbard, Alun Lloyd (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-25)
      The Greenland Ice Sheet harbours a wealth of microbial life, yet the total biomass stored or exported from its surface to downstream environments is unconstrained. Here, we quantify microbial abundance and cellular biomass flux within the near-surface weathering crust photic zone of the western sector of the ice sheet. Using groundwater techniques, we demonstrate that interstitial water flow is slow ...

    • Surface Meltwater Impounded by Seasonal Englacial Storage in West Greenland 

      Kendrick, A.K.; Schroeder, D.M.; Chu, W.; Young, T.J.; Christoffersen, P.; Todd, J.; Doyle, S.H.; Box, J.E.; Hubbard, A.; Hubbard, B.; Brennan, P.V.; Nicholls, K. W.; Lok, L.B. (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-24)
      The delivery of surface meltwater through englacial drainage systems to the bed of the Greenland Ice Sheet modulates ice flow through basal lubrication. Recent studies in Southeast Greenland have identified a perennial firn aquifer; however, there are few observations quantifying the input or residence time of water within the englacial system and it remains unknown whether water can be stored within ...