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| Titel |
Variability of polar snow densification during climatic transitions |
| VerfasserIn |
Camille Bréant, Patricia Martinerie, Amaëlle Landais, Laurent Arnaud |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250110335
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| Publikation (Nr.) |
 EGU/EGU2015-10319.pdf |
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| Zusammenfassung |
| The transformation of snow into ice is a complex natural phenomenon and difficult to model.
Depending on temperature and precipitation conditions, it may take several decades to
millennia. This process is the cause of the age difference between the ice and the gases it
contains. The prediction of gas trapping depth is a major challenge of paleoclimatology. The
wide discrepancies observed in central Antarctica between densification model outputs and
isotopic measurements of inert gases trapped in ice generate important uncertainty in past
climate reconstructions.
The LGGE thermo-mechanical model of firn densification includes the formulation of
mechanical processes, thermal properties, and gas trapping criteria. The model performances
have been tested against measurements of present-day density and temperature profiles, and
trace gas data in ice cores (15N, 40Ar, CH4). Several ice cores are simulated with consistent
model parameters. The model has been improved based on sensitivity tests and new
experimental constraints (e.g. thermal properties such as activation energies, mechanical
parameters: critical density, coordination number etc.). We will present the impact of model
improvements on the variations of delta-depth/delta-age during climatic transitions. |
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