Fluctuations of a Greenlandic tidewater glacier driven by changes in atmospheric forcing

observations and modelling of Kangiata Nunaata Sermia, 1859–present

J. M. Lea, D. W. F. Mair, F. M. Nick, B. R. Rea, D. van As, M. Morlighem, P. W. Nienow, A. Weidick

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Abstract

Many tidewater glaciers in Greenland are known to have undergone significant retreat during the last century following their Little Ice Age maxima. Where it is possible to reconstruct glacier change over this period, they provide excellent records for comparison to climate records, and calibration/validation for numerical models. These records therefore allow tests of numerical models that seek to simulate tidewater glacier behaviour over multi-decadal to centennial timescales. Here we present a detailed record of behaviour from Kangiata Nunaata Sermia (KNS), SW Greenland, between 1859–2012 and compare it against available oceanographic and atmospheric temperature variability between 1871–2012. We also use these records to evaluate the ability of a well-established one-dimensional flow-band model to replicate behaviour for the observation period. The record of terminus change demonstrates that KNS has advanced/retreated in phase with atmosphere and ocean climate anomalies averaged over multi-annual to decadal timescales. Results from an ensemble of model runs demonstrate that observed dynamics can be replicated, with changes in atmospheric forcing not needing to be offset by changes in oceanic forcing sensitivity. Furthermore, successful runs always require a significant atmospheric forcing component, while an oceanic forcing component is not always needed. Although the importance of oceanic forcing cannot be discounted, these results demonstrate that changes in atmospheric forcing are likely to be a primary driver of the terminus fluctuations of KNS from 1859–2012.
Original languageEnglish
Pages (from-to)2031-2045
Number of pages16
JournalThe Cryosphere Discussions
Volume8
Issue number6
DOIs
Publication statusPublished - 5 Nov 2014

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tidewater glacier
atmospheric forcing
modeling
timescale
Little Ice Age
climate
glacier
air temperature
calibration
anomaly
atmosphere
ocean

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Fluctuations of a Greenlandic tidewater glacier driven by changes in atmospheric forcing : observations and modelling of Kangiata Nunaata Sermia, 1859–present. / Lea, J. M.; Mair, D. W. F.; Nick, F. M. ; Rea, B. R.; van As, D.; Morlighem, M. ; Nienow, P. W.; Weidick, A. .

In: The Cryosphere Discussions, Vol. 8, No. 6, 05.11.2014, p. 2031-2045.

Research output: Contribution to journalArticle

Lea, J. M. ; Mair, D. W. F. ; Nick, F. M. ; Rea, B. R. ; van As, D. ; Morlighem, M. ; Nienow, P. W. ; Weidick, A. . / Fluctuations of a Greenlandic tidewater glacier driven by changes in atmospheric forcing : observations and modelling of Kangiata Nunaata Sermia, 1859–present. In: The Cryosphere Discussions. 2014 ; Vol. 8, No. 6. pp. 2031-2045.
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title = "Fluctuations of a Greenlandic tidewater glacier driven by changes in atmospheric forcing: observations and modelling of Kangiata Nunaata Sermia, 1859–present",
abstract = "Many tidewater glaciers in Greenland are known to have undergone significant retreat during the last century following their Little Ice Age maxima. Where it is possible to reconstruct glacier change over this period, they provide excellent records for comparison to climate records, and calibration/validation for numerical models. These records therefore allow tests of numerical models that seek to simulate tidewater glacier behaviour over multi-decadal to centennial timescales. Here we present a detailed record of behaviour from Kangiata Nunaata Sermia (KNS), SW Greenland, between 1859–2012 and compare it against available oceanographic and atmospheric temperature variability between 1871–2012. We also use these records to evaluate the ability of a well-established one-dimensional flow-band model to replicate behaviour for the observation period. The record of terminus change demonstrates that KNS has advanced/retreated in phase with atmosphere and ocean climate anomalies averaged over multi-annual to decadal timescales. Results from an ensemble of model runs demonstrate that observed dynamics can be replicated, with changes in atmospheric forcing not needing to be offset by changes in oceanic forcing sensitivity. Furthermore, successful runs always require a significant atmospheric forcing component, while an oceanic forcing component is not always needed. Although the importance of oceanic forcing cannot be discounted, these results demonstrate that changes in atmospheric forcing are likely to be a primary driver of the terminus fluctuations of KNS from 1859–2012.",
author = "Lea, {J. M.} and Mair, {D. W. F.} and Nick, {F. M.} and Rea, {B. R.} and {van As}, D. and M. Morlighem and Nienow, {P. W.} and A. Weidick",
note = "Acknowledgements. The authors wish to thank Stephen Price, Mauri Pelto, and the anonymous reviewer for their reviews and comments that helped to improve the manuscript. RACMO2.1 data were provided by Jan van Angelen and Michiel van den Broeke, IMAU, Utrecht University. MAR v3.2 data used for runoff calculations were provided by Xavier Fettweis, Department of Geography, University of Li{\`e}ge. The photogrammetric DEM used in Figs. 1 and 3 was provided by Kurt H. Kj{\ae}r, Centre for GeoGenetics, University of Copenhagen. This research was financially supported by J. M. Lea’s PhD funding, NERC grant number NE/I528742/1. Support for F. M. Nick was provided through the Conoco-Phillips/Lundin Northern Area Program CRIOS project (Calving Rates and Impact on Sea Level).",
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T2 - observations and modelling of Kangiata Nunaata Sermia, 1859–present

AU - Lea, J. M.

AU - Mair, D. W. F.

AU - Nick, F. M.

AU - Rea, B. R.

AU - van As, D.

AU - Morlighem, M.

AU - Nienow, P. W.

AU - Weidick, A.

N1 - Acknowledgements. The authors wish to thank Stephen Price, Mauri Pelto, and the anonymous reviewer for their reviews and comments that helped to improve the manuscript. RACMO2.1 data were provided by Jan van Angelen and Michiel van den Broeke, IMAU, Utrecht University. MAR v3.2 data used for runoff calculations were provided by Xavier Fettweis, Department of Geography, University of Liège. The photogrammetric DEM used in Figs. 1 and 3 was provided by Kurt H. Kjær, Centre for GeoGenetics, University of Copenhagen. This research was financially supported by J. M. Lea’s PhD funding, NERC grant number NE/I528742/1. Support for F. M. Nick was provided through the Conoco-Phillips/Lundin Northern Area Program CRIOS project (Calving Rates and Impact on Sea Level).

PY - 2014/11/5

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N2 - Many tidewater glaciers in Greenland are known to have undergone significant retreat during the last century following their Little Ice Age maxima. Where it is possible to reconstruct glacier change over this period, they provide excellent records for comparison to climate records, and calibration/validation for numerical models. These records therefore allow tests of numerical models that seek to simulate tidewater glacier behaviour over multi-decadal to centennial timescales. Here we present a detailed record of behaviour from Kangiata Nunaata Sermia (KNS), SW Greenland, between 1859–2012 and compare it against available oceanographic and atmospheric temperature variability between 1871–2012. We also use these records to evaluate the ability of a well-established one-dimensional flow-band model to replicate behaviour for the observation period. The record of terminus change demonstrates that KNS has advanced/retreated in phase with atmosphere and ocean climate anomalies averaged over multi-annual to decadal timescales. Results from an ensemble of model runs demonstrate that observed dynamics can be replicated, with changes in atmospheric forcing not needing to be offset by changes in oceanic forcing sensitivity. Furthermore, successful runs always require a significant atmospheric forcing component, while an oceanic forcing component is not always needed. Although the importance of oceanic forcing cannot be discounted, these results demonstrate that changes in atmospheric forcing are likely to be a primary driver of the terminus fluctuations of KNS from 1859–2012.

AB - Many tidewater glaciers in Greenland are known to have undergone significant retreat during the last century following their Little Ice Age maxima. Where it is possible to reconstruct glacier change over this period, they provide excellent records for comparison to climate records, and calibration/validation for numerical models. These records therefore allow tests of numerical models that seek to simulate tidewater glacier behaviour over multi-decadal to centennial timescales. Here we present a detailed record of behaviour from Kangiata Nunaata Sermia (KNS), SW Greenland, between 1859–2012 and compare it against available oceanographic and atmospheric temperature variability between 1871–2012. We also use these records to evaluate the ability of a well-established one-dimensional flow-band model to replicate behaviour for the observation period. The record of terminus change demonstrates that KNS has advanced/retreated in phase with atmosphere and ocean climate anomalies averaged over multi-annual to decadal timescales. Results from an ensemble of model runs demonstrate that observed dynamics can be replicated, with changes in atmospheric forcing not needing to be offset by changes in oceanic forcing sensitivity. Furthermore, successful runs always require a significant atmospheric forcing component, while an oceanic forcing component is not always needed. Although the importance of oceanic forcing cannot be discounted, these results demonstrate that changes in atmospheric forcing are likely to be a primary driver of the terminus fluctuations of KNS from 1859–2012.

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DO - 10.5194/tc-8-2031-2014

M3 - Article

VL - 8

SP - 2031

EP - 2045

JO - The Cryosphere Discussions

JF - The Cryosphere Discussions

SN - 1994-0432

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ER -