EGU2020-19249
https://doi.org/10.5194/egusphere-egu2020-19249
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

The genesis of a climate archive: snow pack studies at four polar sites

Johannes Freitag1, Maria Hörhold1, Alexander Weinhart1, Sepp Kipfstuhl1, and Thomas Laepple2,3
Johannes Freitag et al.
  • 1Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Glaciology, Bremerhaven, Germany (johannes.freitag@awi.de)
  • 2Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, ECUS,Potsdam, Germany (johannes.freitag@awi.de)
  • 3Institute of Environmental Physics, University of Bremen, Germany

Understanding the deposition history and signal formation in ice cores from polar ice sheets is fundamental for the interpretation of paleoclimate reconstruction based on climate proxies. Polar surface snow responds to environmental changes on a seasonal time scale by snow metamorphism, displayed in the snow microstructure and archived in the snowpack. However, the seasonality of snow metamorphism and its link to the deposited signal in isotopes and impurity load is poorly known.

Here, we apply core-scale microfocus X-ray computer tomography to continuously measure snow microstructure of four snow cores from Greenlandic (Renland ice cap-drill site (2m), EASTGRIP drill site (5m)) and Antarctic sites (EDML-drill site (3m), COFI7/Plateau station (4m)) covering a wide range of annual temperatures from -18°C down to -56°C. In our multi-parameter approach we compare the derived microstructural properties on the mm- to cm-scale to discretely measured trace components and stable water isotopes, commonly used as climate proxies. We will show how ice and pore intercepts, the geometrical anisotropy, specific surface area, crusts anomalies and small-scale density distributions are represented under different climate conditions. Their profiles will be discussed in the context of snow metamorphism and deposition history using trace components and isotopes as additional constraints on timing.

How to cite: Freitag, J., Hörhold, M., Weinhart, A., Kipfstuhl, S., and Laepple, T.: The genesis of a climate archive: snow pack studies at four polar sites, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19249, https://doi.org/10.5194/egusphere-egu2020-19249, 2020

Comments on the presentation

AC: Author Comment | CC: Community Comment | Report abuse

Presentation version 1 – uploaded on 07 May 2020 , no comments