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Titel |
Fluctuations of a Greenlandic tidewater glacier driven by changes in atmospheric forcing: observations and modelling of Kangiata Nunaata Sermia, 1859-present |
VerfasserIn |
J. M. Lea, D. W. F. Mair, F. M. Nick, B. R. Rea, D. As, M. Morlighem, P. W. Nienow, A. Weidick |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1994-0416
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Digitales Dokument |
URL |
Erschienen |
In: The Cryosphere ; 8, no. 6 ; Nr. 8, no. 6 (2014-11-05), S.2031-2045 |
Datensatznummer |
250116373
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Publikation (Nr.) |
copernicus.org/tc-8-2031-2014.pdf |
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Zusammenfassung |
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, as well as
calibration/validation for numerical models. These glacier change records
therefore allow for 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 and 2012, and compare it against available
oceanographic and atmospheric temperature data between 1871 and 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. Model
runs that provide a reasonable match to observations always require a
significant atmospheric forcing component, but do not necessarily require an
oceanic forcing component. 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 to 2012. We propose that the detail and length of the record presented
makes KNS an ideal site for model validation exercises investigating links
between climate, calving rates, and tidewater glacier dynamics. |
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