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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

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posted on 16.04.2013 by Richard Hodgkins, Richard Cooper, Martyn Tranter, Jemma Wadham
The 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 Research

Volume

49

Issue

7

Pages

4230 - 4243

Citation

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 Union

Version

VoR (Version of Record)

Rights holder

© The Authors

Publisher 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

12/04/2013

Publication date

2013-07-26

Copyright date

2013

ISSN

0043-1397

eISSN

1944-7973

Language

en

Licence

Exports