On the impact of impurities on the densification of polar firn ...

Understanding polar firn densification is crucial for reconstructing the age of greenhouse gas concentrations extracted from ice cores, and for the interpretation of air in ice as a dating tool or as a climate proxy. Firn densification is generally modeled as a steady burial and sintering process of...

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Bibliographic Details
Main Authors: Hörhold, Maria, Laepple, Thomas, Freitag, Johannes, Bigler, Matthias, Fischer, Hubertus, Kipfstuhl, Sepp
Format: Text
Language:unknown
Published: :unas 2012
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Online Access:https://dx.doi.org/10.57694/7259
https://phrepo.phbern.ch/7259/
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Summary:Understanding polar firn densification is crucial for reconstructing the age of greenhouse gas concentrations extracted from ice cores, and for the interpretation of air in ice as a dating tool or as a climate proxy. Firn densification is generally modeled as a steady burial and sintering process of defined layers, where the structure of the layering is maintained along the whole firn and ice column. However, available high-resolution density data, as well as firn air samples, question this picture and point to a lack of understanding of firn densification. Based on analysis of high-resolution density and calcium concentration records from Antarctic and Greenland ice cores, we show for the first time that also impurities may have a significant impact on the densification. Analysis of firn cores shows a correlation between density and the calcium ion (Ca++) concentration, and this correlation increases with depth. The existence of this relationship is independent of the local climatic conditions at the core ...