In situ measurements of meltwater flow through snow and firn in the accumulation zone of the SW Greenland Ice Sheet
-
Published:2022-10-19
Issue:10
Volume:16
Page:4379-4401
-
ISSN:1994-0424
-
Container-title:The Cryosphere
-
language:en
-
Short-container-title:The Cryosphere
Author:
Clerx NicoleORCID, Machguth HorstORCID, Tedstone AndrewORCID, Jullien NicolasORCID, Wever NanderORCID, Weingartner Rolf, Roessler Ole
Abstract
Abstract. The Greenland Ice Sheet is losing mass, part of which is caused by increasing runoff. The location of the runoff limit, the highest elevation from which meltwater finds its way off the ice sheet, plays an important role in the surface mass balance of the ice sheet. The recently observed rise in runoff area might be related to an increasing amount of refreezing: ice layer development in the firn reduces vertical percolation and promotes lateral runoff. To investigate meltwater flow near the runoff limit in the accumulation zone on the southwestern Greenland Ice Sheet, we carried out in situ measurements of hydrological processes and properties of firn and snow. The hydraulic conductivity of icy firn in pre-melt conditions measured using a portable lysimeter ranges from 0.17 to 12.8 m h−1, with flow predominantly occurring through preferential flow fingers. Lateral flow velocities of meltwater on top of the near-surface ice slab, measured at the peak of the melt season by salt dilution and tracer experiments, range from 1.3 to
15.1 m h−1. With these lateral flow velocities, the distance between the slush limit, the highest elevation where liquid water is visible on the ice sheet surface, and the runoff limit could be roughly 4 km in regions where near-surface ice slabs are present. These measurements are a first step towards an integrated set of hydrological properties of firn on the SW Greenland Ice Sheet and show evidence that meltwater runoff may occur from elevations above the visible runoff area.
Funder
HORIZON EUROPE European Research Council Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
Publisher
Copernicus GmbH
Subject
Earth-Surface Processes,Water Science and Technology
Reference107 articles.
1. Adolph, A. C. and Albert, M. R.: Gas diffusivity and permeability through the firn column at Summit, Greenland: measurements and comparison to microstructural properties, The Cryosphere, 8, 319–328, https://doi.org/10.5194/tc-8-319-2014, 2014. a 2. Ahlstrøm, A., Gravesen, P., Andersen, S., van As, D., Citterio, M.,
Fausto, R., Nielsen, S., Jepsen, H., Kristensen, S., Christensen, E.,
Stenseng, L., Forsberg, R., Hanson, S., and Petersen, D.: A new programme for
monitoring the mass loss of the Greenland ice sheet, Geological Survey of Denmark and Greenland Bulletin, 15, 61–64, https://doi.org/10.34194/geusb.v15.5045, 2008. a, b 3. Albert, M. R., Shultz, E. F., and Perron, F. E.: Snow and firn permeability at
Siple Dome, Antarctica, Ann. Glaciol., 31, 353–356,
https://doi.org/10.3189/172756400781820273, 2000. a 4. Ambach, W.: Untersuchungen zum Energieumsatz in der Ablationszone des
Grönländischen Inlandeises, Meddelelser om Grønland, 174, 1–311,
1963. a 5. Ambach, W., Blumthaler, M., Eisner, H., Kirchlechner, P., Schneider, H.,
Behrens, H., Moser, H., Oerter, H., Rauert, W., and Bergman, H.:
Untersuchungen der Wassertafel am Kesselwandferner (Ötztaler Alpen) an einem
30 Meter tiefen Firnschacht, Zeitschrift für Gletscherkunde und
Glazialgeologie, 14, 61–71, 1978.
Cited by
10 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|