EGU21-14089, updated on 04 Mar 2021
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Estimating the diffusion length in the deepest section of ice cores; A case study for MIS19 in Dome-C

Thomas Laepple, Thomas Münch, Torben Kunz, Mathieu Casado, and Maria Hoerhold
Thomas Laepple et al.
  • Alfred-Wegener-Institut, Helmholtz Centre for Polar and Marine Research, Germany (

To recover very old climate information from ice core records, one needs to interpret the deepest part of an ice core. As the oldest record, the Dome-C ice core can serve as an analogue for the Beyond EPICA Oldest Ice Core that is currently being drilled.

Pol et al., EPSL 2010 analyzed high resolution water isotope data from the Dome-C ice core and found evidence for a limited preservation of climate variability in the deep section of the core due to mixing and diffusion. For instance, for Marine Isotope Stage 19, the study estimated a mixing/diffusion length between 40 and 60 cm, a value more than double than what is predicted by current firn and ice diffusion models. Knowing the diffusion length is important to interpret the isotope signal and is the basis to deconvolve climate records. As a result, it is key to bridge the gap in the estimation of the diffusion length between potentially biased statistical methods and firn and ice diffusion models.
We review this diffusion length estimate for MIS19, and also outline a new general method how to estimate the diffusion length in highly thinned deep ice.  This approach presents an important tool for better characterizing the preservation of the climate signal in old ice and thus for designing optimal sampling and recovery strategies.


How to cite: Laepple, T., Münch, T., Kunz, T., Casado, M., and Hoerhold, M.: Estimating the diffusion length in the deepest section of ice cores; A case study for MIS19 in Dome-C, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14089,, 2021.


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