The contrasting response of outlet glaciers to interior and ocean forcing

The dynamics of marine-terminating outlet glaciers are of fundamental interest in glaciology and affect mass loss from ice sheets in a warming climate. In this study, we analyze the response of outlet glaciers to different sources of climate forcing. We find that outlet glaciers have a characteristi...

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Published in:The Cryosphere
Main Authors: J. E. Christian, A. A. Robel, C. Proistosescu, G. Roe, M. Koutnik, K. Christianson
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2020
Subjects:
geo
Online Access:https://doi.org/10.5194/tc-14-2515-2020
https://tc.copernicus.org/articles/14/2515/2020/tc-14-2515-2020.pdf
https://doaj.org/article/f0dc9f70ea2a48de8b3bebdc54636890
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spelling fttriple:oai:gotriple.eu:oai:doaj.org/article:f0dc9f70ea2a48de8b3bebdc54636890 2023-05-15T18:32:16+02:00 The contrasting response of outlet glaciers to interior and ocean forcing J. E. Christian A. A. Robel C. Proistosescu G. Roe M. Koutnik K. Christianson 2020-07-01 https://doi.org/10.5194/tc-14-2515-2020 https://tc.copernicus.org/articles/14/2515/2020/tc-14-2515-2020.pdf https://doaj.org/article/f0dc9f70ea2a48de8b3bebdc54636890 en eng Copernicus Publications doi:10.5194/tc-14-2515-2020 1994-0416 1994-0424 https://tc.copernicus.org/articles/14/2515/2020/tc-14-2515-2020.pdf https://doaj.org/article/f0dc9f70ea2a48de8b3bebdc54636890 undefined The Cryosphere, Vol 14, Pp 2515-2535 (2020) envir geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2020 fttriple https://doi.org/10.5194/tc-14-2515-2020 2023-01-22T17:32:44Z The dynamics of marine-terminating outlet glaciers are of fundamental interest in glaciology and affect mass loss from ice sheets in a warming climate. In this study, we analyze the response of outlet glaciers to different sources of climate forcing. We find that outlet glaciers have a characteristically different transient response to surface-mass-balance forcing applied over the interior than to oceanic forcing applied at the grounding line. A recently developed reduced model represents outlet-glacier dynamics via two widely separated response timescales: a fast response associated with grounding-zone dynamics and a slow response of interior ice. The reduced model is shown to emulate the behavior of a more complex numerical model of ice flow. Together, these models demonstrate that ocean forcing first engages the fast, local response and then the slow adjustment of interior ice, whereas surface-mass-balance forcing is dominated by the slow interior adjustment. We also demonstrate the importance of the timescales of stochastic forcing for assessing the natural variability in outlet glaciers, highlighting that decadal persistence in ocean variability can affect the behavior of outlet glaciers on centennial and longer timescales. Finally, we show that these transient responses have important implications for attributing observed glacier changes to natural or anthropogenic influences; the future change already committed by past forcing; and the impact of past climate changes on the preindustrial glacier state, against which current and future anthropogenic influences are assessed. Article in Journal/Newspaper The Cryosphere Unknown The Cryosphere 14 7 2515 2535
institution Open Polar
collection Unknown
op_collection_id fttriple
language English
topic envir
geo
spellingShingle envir
geo
J. E. Christian
A. A. Robel
C. Proistosescu
G. Roe
M. Koutnik
K. Christianson
The contrasting response of outlet glaciers to interior and ocean forcing
topic_facet envir
geo
description The dynamics of marine-terminating outlet glaciers are of fundamental interest in glaciology and affect mass loss from ice sheets in a warming climate. In this study, we analyze the response of outlet glaciers to different sources of climate forcing. We find that outlet glaciers have a characteristically different transient response to surface-mass-balance forcing applied over the interior than to oceanic forcing applied at the grounding line. A recently developed reduced model represents outlet-glacier dynamics via two widely separated response timescales: a fast response associated with grounding-zone dynamics and a slow response of interior ice. The reduced model is shown to emulate the behavior of a more complex numerical model of ice flow. Together, these models demonstrate that ocean forcing first engages the fast, local response and then the slow adjustment of interior ice, whereas surface-mass-balance forcing is dominated by the slow interior adjustment. We also demonstrate the importance of the timescales of stochastic forcing for assessing the natural variability in outlet glaciers, highlighting that decadal persistence in ocean variability can affect the behavior of outlet glaciers on centennial and longer timescales. Finally, we show that these transient responses have important implications for attributing observed glacier changes to natural or anthropogenic influences; the future change already committed by past forcing; and the impact of past climate changes on the preindustrial glacier state, against which current and future anthropogenic influences are assessed.
format Article in Journal/Newspaper
author J. E. Christian
A. A. Robel
C. Proistosescu
G. Roe
M. Koutnik
K. Christianson
author_facet J. E. Christian
A. A. Robel
C. Proistosescu
G. Roe
M. Koutnik
K. Christianson
author_sort J. E. Christian
title The contrasting response of outlet glaciers to interior and ocean forcing
title_short The contrasting response of outlet glaciers to interior and ocean forcing
title_full The contrasting response of outlet glaciers to interior and ocean forcing
title_fullStr The contrasting response of outlet glaciers to interior and ocean forcing
title_full_unstemmed The contrasting response of outlet glaciers to interior and ocean forcing
title_sort contrasting response of outlet glaciers to interior and ocean forcing
publisher Copernicus Publications
publishDate 2020
url https://doi.org/10.5194/tc-14-2515-2020
https://tc.copernicus.org/articles/14/2515/2020/tc-14-2515-2020.pdf
https://doaj.org/article/f0dc9f70ea2a48de8b3bebdc54636890
genre The Cryosphere
genre_facet The Cryosphere
op_source The Cryosphere, Vol 14, Pp 2515-2535 (2020)
op_relation doi:10.5194/tc-14-2515-2020
1994-0416
1994-0424
https://tc.copernicus.org/articles/14/2515/2020/tc-14-2515-2020.pdf
https://doaj.org/article/f0dc9f70ea2a48de8b3bebdc54636890
op_rights undefined
op_doi https://doi.org/10.5194/tc-14-2515-2020
container_title The Cryosphere
container_volume 14
container_issue 7
container_start_page 2515
op_container_end_page 2535
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