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| Titel |
Reconstructing the post-LGM decay of the Eurasian Ice Sheets with Ice Sheet Models; data-model comparison and focus on the Storfjorden (Svalbard) ice stream dynamics history |
| VerfasserIn |
Michele Petrini, Nina Kirchner, Florence Colleoni, Angelo Camerlenghi, Michele Rebesco, Renata G. Lucchi, Emanuele Forte, Renato R. Colucci |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250141004
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| Publikation (Nr.) |
 EGU/EGU2017-4464.pdf |
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| Zusammenfassung |
| The challenge of reconstructing palaeo-ice sheets past growth and decay represent a critical
task to better understand mechanisms of present and future global climate change. Last
Glacial Maximum (LGM), and the subsequent deglaciation until Pre-Industrial
time (PI) represent an excellent testing ground for numerical Ice Sheet Models
(ISMs), due to the abundant data available that can be used in an ISM as boundary
conditions, forcings or constraints to test the ISMs results. In our study, we simulate
with ISMs the post-LGM decay of the Eurasian Ice Sheets, with a focus on the
marine-based Svalbard-Barents Sea-Kara Sea Ice Sheet. In particular, we aim to reconstruct
the Storfjorden ice stream dynamics history by comparing the model results with
the marine geological data (MSGLs, GZWs, sediment cores analysis) available
from the area, e.g., Pedrosa et al. 2011, Rebesco et al. 2011, 2013, Lucchi et al.
2013. Two hybrid SIA/SSA ISMs are employed, GRISLI, Ritz et al. 2001, and
PSU, Pollard&DeConto 2012. These models differ mainly in the complexity with
which grounding line migration is treated. Climate forcing is interpolated by means
of climate indexes between LGM and PI climate. Regional climate indexes are
constructed based on the non-accelerated deglaciation transient experiment carried
out with CCSM3, Liu et al. 2009. Indexes representative of the climate evolution
over Siberia, Svalbard and Scandinavia are employed. The impact of such refined
representation as opposed to the common use of the NGRIP δ18O index for transient
experiments is analysed. In this study, the ice-ocean interaction is crucial to reconstruct
the Storfjorden ice stream dynamics history. To investigate the sensitivity of the
ice shelf/stream retreat to ocean temperature, we allow for a space-time variation
of basal melting under the ice shelves by testing two-equations implementations
based on Martin et al. 2011 forced with simulated ocean temperature and salinity
from the TraCE-21ka coupled climate simulation. In this presentation, we will
show work in progress, address open issues, and sketch future work. In particular,
we invite the community to suggest possibilities for model-data comparison and
integration.
Liu, Z., Otto-Bliesner, B.L., He, F., Brady, E.C., Tomas, R., Clark, P.U., Carlson, A.E.,
Lynch-Stieglitz, J., Curry, W., Brook, E. and Erickson, D., 2009. Transient simulation of last
deglaciation with a new mechanism for Bólling-Alleród warming. Science, 325(5938),
pp.310-314.
Lucchi, R.G., Camerlenghi, A., Rebesco, M., Colmenero-Hidalgo, E., Sierro, F.J.,
Sagnotti, L., Urgeles, R., Melis, R., Morigi, C., Bárcena, M.A. and Giorgetti, G., 2013.
Postglacial sedimentary processes on the Storfjorden and Kveithola trough mouth fans:
Significance of extreme glacimarine sedimentation. Global and planetary change, 111,
pp.309-326.
Martin, M.A., Winkelmann, R., Haseloff, M., Albrecht, T., Bueler, E., Khroulev, C. and
Levermann, A., 2011. The Potsdam Parallel Ice Sheet Model (PISM-PIK)–Part 2:
Dynamic equilibrium simulation of the Antarctic ice sheet. The Cryosphere, 5(3),
pp.727-740.
Pedrosa, M.T., Camerlenghi, A., De Mol, B., Urgeles, R., Rebesco, M. and Lucchi, R.G.,
2011. Seabed morphology and shallow sedimentary structure of the Storfjorden and
Kveithola trough-mouth fans (north west Barents Sea). Marine Geology, 286(1),
pp.65-81.
Pollard, D. and DeConto, R.M., 2012. Description of a hybrid ice sheet-shelf model, and
application to Antarctica. Geoscientific Model Development, 5(5), pp.1273-1295.
Rebesco, M., Liu, Y., Camerlenghi, A., Winsborrow, M., Laberg, J.S., Caburlotto, A.,
Diviacco, P., Accettella, D., Sauli, C., Wardell, N. and Tomini, I., 2011. Deglaciation of the
western margin of the Barents Sea Ice Sheet–a swath bathymetric and sub-bottom seismic
study from the Kveithola Trough. Marine Geology, 279(1), pp.141-147.
Rebesco, M., Laberg, J., Pedrosa, M., Camerlenghi, A., Lucchi, R., Zgur, F. and Wardell,
N., 2013. Onset and growth of Trough-Mouth Fans on the North-Western Barents Sea margin
e implications for the evolution of the Barents Sea/Svalbard Ice Sheet. Quaternary Science
Reviews, 30, pp.1-8.
Ritz, C., Rommelaere, V. and Dumas, C., 2001. Modeling the evolution of Antarctic ice
sheet over the last 420,000 years: Implications for altitude changes in the Vostok region.
Journal of Geophysical Research: Atmospheres, 106(D23), pp.31943-31964. |
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