World Library  


Add to Book Shelf
Flag as Inappropriate
Email this Book

Simulating the Growth of Supra-glacial Lakes at the Western Margin of the Greenland Ice Sheet : Volume 6, Issue 2 (30/03/2012)

By Leeson, A. A.

Click here to view

Book Id: WPLBN0004022656
Format Type: PDF Article :
File Size: Pages 30
Reproduction Date: 2015

Title: Simulating the Growth of Supra-glacial Lakes at the Western Margin of the Greenland Ice Sheet : Volume 6, Issue 2 (30/03/2012)  
Author: Leeson, A. A.
Volume: Vol. 6, Issue 2
Language: English
Subject: Science, Cryosphere, Discussions
Collections: Periodicals: Journal and Magazine Collection, Copernicus GmbH
Historic
Publication Date:
2012
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

Citation

APA MLA Chicago

Sundal, A., Palmer, S., Leeson, A. A., Fettweis, X., & Shepherd, A. (2012). Simulating the Growth of Supra-glacial Lakes at the Western Margin of the Greenland Ice Sheet : Volume 6, Issue 2 (30/03/2012). Retrieved from http://nook-library.net/


Description
Description: School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK. We present a method of modelling the growth of supra-glacial lakes at the western margin of the Greenland ice sheet, based on routeing runoff estimated by a Regional Climate Model (RCM) across a digital elevation model (DEM) of the ice sheet surface. Using data acquired during the 2003 melt season, we demonstrate that the model is 18 times more likely to correctly predict the presence or absence of lakes identified in MODIS satellite imagery within an elevation range of 1000 to 1600 metres above sea level (m.a.s.l.) than it is to make incorrect predictions. Our model does not, however, simulate processes leading to lake stagnation or decay, such as refreezing or drainage – a process which affects approximately 17% of lakes in our study area (Selmes et al., 2011). This likely explains much of why our model over-predicts cumulative area by 32% although other factors including uncertainty in the DEM and in the MODIS derived observations used for validation contribute to this error. Simulated lake filling tends to lead observations by approximately 5 days which could be related to a filling period required to saturate cracks, crevasses and other porous space within the ice. We find that the maximum modelled lake covered ice sheet area is 6% and suggest that this is a topographic limitation for this sector. We can take this as an upper bound; given the absence of drainage in the model. In 2003, the difference between RCM estimates of runoff and the maximum volume of water simulated to be stored in lakes was 12.49 km3. This can be taken as a measure of potential water available for lubrication and is calculated to be 1.86 m3 per square metre of ice. This study has proved a good first step towards capturing the variability of supra-glacial lake evolution with a numerical model; we are optimistic that the model will develop further into a useful tool for use in analysing the behaviour of supra-glacial lakes on the Greenland ice sheet in the present day and beyond.

Summary
Simulating the growth of supra-glacial lakes at the western margin of the Greenland ice sheet

Excerpt
Box, J. E. and Ski, K.: Remote sounding of Greenland supraglacial melt lakes: implications for subglacial hydraulics, J. Glaciol., 53, 257–265, 2007.; Bamber, J. L., Layberry, R. L., and Gogineni, S.: A new ice thickness and bed data set for the Greenland ice sheet 1. Measurement, data reduction, and errors, J. Geophys. Res.-Atmos., 106, 33773–33780, 2001.; Bartholomew, I. D., Nienow, P., Sole, A., Mair, D., Cowton, T., King, M. A., and Palmer, S.: Seasonal variations in Greenland Ice Sheet motion: Inland extent and behaviour at higher elevations, Earth Planet. Sci. Lett., 307, 271–278, doi:10.1016/j.epsl.2011.04.014, 2011.; Das, S. B., Joughin, I., Behn, M. D., Howat, I. M., King, M. A., Lizarralde, D., and Bhatia, M. P.: Fracture propagation to the base of the Greenland Ice Sheet during supraglacial lake drainage, Science, 320, 778–781, doi:10.1126/science.1153360, 2008.; Echelmeyer, K., Clarke, T. S., and Harrison, W. D.: Surficial glaciology of Jakobshavns Isbrae, West Greenland .1. Surface-Morphology, J. Glaciol., 37, 368–382, 1991.; Ettema, J., van den Broeke, M. R., van Meijgaard, E., van de Berg, W. J., Box, J. E., and Steffen, K.: Climate of the Greenland ice sheet using a high-resolution climate model – Part 1: Evaluation, The Cryosphere, 4, 511–527, doi:10.5194/tc-4-511-2010, 2010.; Fettweis, X.: Reconstruction of the 1979�2006 Greenland ice sheet surface mass balance using the regional climate model MAR, The Cryosphere, 1, 21–40, doi:10.5194/tc-1-21-2007, 2007.; Fettweis, X., Tedesco, M., van den Broeke, M., and Ettema, J.: Melting trends over the Greenland ice sheet (1958–2009) from spaceborne microwave data and regional climate models, The Cryosphere, 5, 359–375, doi:10.5194/tc-5-359-2011, 2011.; Franco, B., Fettweis, X., Lang, C., and Erpicum, M.: Impact of spatial resolution on the modelling of the Greenland ice sheet surface mass balance between 1990–2010, using the regional climate model MAR, The Cryosphere Discuss., 6, 635–672, doi:10.5194/tcd-6-635-2012, 2012.; Georgiou, S., Shepherd, A., McMillan, M., and Nienow, P.: Seasonal evolution of supraglacial lake volume from ASTER imagery, Ann. Glaciol., 50, 95–100, 2009.; Gudmundsson, G. H.: Transmission of basal variability to a glacier surface, J. Geophys. Res.-Sol. Ea., 108, 2253, doi:10.1029/2002jb002107, 2003.; Joughin, I., Winebrenner, D., Fahnestock, M., Kwok, R., and Krabill, W.: Measurement of ice-sheet topography using satellite radar interferometry, J. Glaciol., 42, 10–22, 1996.; Joughin, I., Das, S. B., King, M. A., Smith, B. E., Howat, I. M., and Moon, T.: Seasonal speedup along the western flank of the Greenland Ice Sheet, Science, 320, 781–783, doi:10.1126/science.1153288, 2008.; Krawczynski, M. J., Behn, M. D., Das, S. B., and Joughin, I.: Constraints on the lake volume required for hydro-fracture through ice sheets, Geophys. Res. Lett., 36, L10501, doi:10.1029/2008gl036765, 2009.; Lefebre, F., Gallee, H., van Ypersele, J. P., and Greuell, W.: Modeling of snow and ice melt at ETH Camp (West Greenland): A study of surface albedo, J. Geophys. Res.-Atmos., 108, 4231, doi:10.1029/2001jd001160, 2003.; Lotter, G. K.: Considerations on hydraulic design of channels with different roughness of walls, Transactions, All-Union Scientific Research Institute of Hydraulic Engineering, Leningrad, 1932.; Luthje, M., Pedersen, L.

 

Click To View

Additional Books


  • Future Arctic Marine Access: Analysis an... (by )
  • The Role of Glaciers in Stream Flow from... (by )
  • Overview on Radon Measurements in Arctic... (by )
  • Constraints on the Δ2H Diffusion Rate in... (by )
  • Seasonal Speed-up of Two Outlet Glaciers... (by )
  • Exploring Uncertainty in Glacier Mass Ba... (by )
  • An Antarctic Monitoring Initiative for F... (by )
  • On the Influence of Model Physics on Sim... (by )
  • Inferring Snow Pack Ripening and Melt Ou... (by )
  • Implementation and Evaluation of Prognos... (by )
  • Sensitivity of a Distributed Temperature... (by )
  • Evidence and Analysis of 2012 Greenland ... (by )
Scroll Left
Scroll Right

 



Copyright © World Library Foundation. All rights reserved. eBooks from Nook eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.