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Drainage-system development in consecutive melt seasons at a polythermal, Arctic glacier, evaluated by flow-recession analysis and linear-reservoir simulation
journal contribution
posted on 2013-04-16, 11:30 authored by Richard HodgkinsRichard Hodgkins, Richard Cooper, Martyn Tranter, Jemma WadhamThe drainage systems of polythermal glaciers play an important role in high latitude hydrology, and are determinants of ice flow rate. Flow-recession analysis and linear-reservoir simulation of runoff time series are here used to evaluate seasonal and inter-annual variability in the drainage system of the polythermal Finsterwalderbreen, Svalbard, in 1999 and 2000. Linear flow recessions are pervasive, with mean coefficients of a fast reservoir varying from 16 h (1999) to 41 h (2000), and mean coefficients of an intermittent, slow reservoir varying from 54 h (1999) to 114 h (2000). Drainage-system efficiency is greater overall in the first of the two seasons, the simplest explanation of which is more rapid depletion of the snow cover. Reservoir coefficients generally decline during each season (at 0.22 h d–1 in 1999 and 0.52 h d–1 in 2000), denoting an increase in drainage efficiency. However, coefficients do not exhibit a consistent relationship with discharge. Finsterwalderbreen therefore appears to behave as an intermediate case between temperate glaciers and other polythermal glaciers with smaller proportions of temperate ice. Linear-reservoir runoff simulations exhibit limited sensitivity to a relatively wide range of reservoir coefficients, although the use of fixed coefficients in a spatially-lumped model can generate significant sub-seasonal error. At Finsterwalderbreen, an ice-marginal channel with the characteristics of a fast reservoir, and a subglacial upwelling with the characteristics of a slow reservoir, both route meltwater to the terminus. This suggests that drainage-system components of significantly contrasting efficiencies can co-exist spatially and temporally at polythermal glaciers.
Funding
This work was supported by NERC [grant number GST/02/ 2204, and tied studentship GT24/98/ARCI/8].
History
School
- Social Sciences and Humanities
Department
- Geography and Environment
Published in
Water Resources ResearchVolume
49Issue
7Pages
4230 - 4243Citation
HODGKINS, R. ... et al., 2013. Drainage-system development in consecutive melt seasons at a polythermal, Arctic glacier, evaluated by flow-recession analysis and linear-reservoir simulation. Water Resources Research, 49 (7), pp. 4230–4243.Publisher
Wiley on behalf of American Geophysical UnionVersion
- VoR (Version of Record)
Rights holder
© The AuthorsPublisher statement
This is an Open Access Article. It is published by Wiley under the Creative Commons Attribution 3.0 Unported Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/3.0/Acceptance date
2013-04-12Publication date
2013-07-26Copyright date
2013ISSN
0043-1397eISSN
1944-7973Publisher version
Language
- en