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The Cryosphere An interactive open-access journal of the European Geosciences Union
https://doi.org/10.5194/tc-2017-104
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
30 Jun 2017
Review status
This discussion paper is a preprint. It is a manuscript under review for the journal The Cryosphere (TC).
Spatial and temporal distributions of surface mass balance between Concordia and Vostok stations, Antarctica from combined radar and ice core data: First results and detailed error analysis
Emmanuel Le Meur1, Olivier Magand1, Laurent Arnaud1, Michel Fily1, Massimo Frezzotti2, Marie Cavitte3, Robert Mulvaney4, and Stefano Urbini5 1University Grenoble Alpes, CNRS, IGE, Grenoble, France
2ENEA, Agenzia Nazionale per le nuove tecnologie, l'energia e lo sviluppo sostenibile, Rome, Italy
3Institute for Geophysics, University of Texas at Austin, Texas, USA
4British Antarctic Survey, Cambridge, UK
5Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy
Abstract. Results from Ground Penetrating Radar (GPR) measurements and shallow ice cores carried out during a scientific traverse between Dome Concordia (DC) and Vostok stations are presented in order to infer both spatial and temporal characteristics of snow accumulation over the East Antarctic plateau. Spatially continuous accumulation rates along the traverse are computed from the identification of three equally spaced radar reflections spanning about the last 600 yr. Accurate dating of these Internal Reflection Horizons (IRHs) is obtained from a depth-age relationship derived from volcanic horizons and bomb testing fallout on a DC ice core and shows a very good consistency when tested against extra ice cores drilled along the radar profile. Accumulation rates are then inferred by accounting for density profiles down to each IRH. For this latter purpose, a careful error analysis showed that using a single and more accurate density profile along a DC core provided more reliable results than trying to include the potential spatial variability in density from extra (but less accurate) ice cores distributed along the profile.

The most striking feature is an accumulation pattern that remains constant through time with persistent gradients such as a marked decrease from 26 mm w.e. yr−1 at DC to 20 mm w.e. yr−1 at the South West end of the profile over the last 234 yr average (with a similar decrease from 25 mm w.e. yr−1 to 19 mm w.e. yr−1 over the last 592 yr). Insights into the time-dependency reveal a steady increase of accumulation on the East Antarctic plateau during the last 600 yr and more particularly since about 200 yr as already suggested by previous studies relying on GPR and/or time markers in ice cores. Maximum margins of error are in the range 4 mm w.e. yr−1 (last 234 yr) to 2 mm w.e. yr−1 (last 592 yr), a decrease with depth mainly resulting from the time-averaging when computing accumulation rates. The gradients proposed in this study remain however significant since only the reduced non systematic component (with regard to space or time) of these error terms has to be considered when interpreting spatial or temporal trends.


Citation: Le Meur, E., Magand, O., Arnaud, L., Fily, M., Frezzotti, M., Cavitte, M., Mulvaney, R., and Urbini, S.: Spatial and temporal distributions of surface mass balance between Concordia and Vostok stations, Antarctica from combined radar and ice core data: First results and detailed error analysis, The Cryosphere Discuss., https://doi.org/10.5194/tc-2017-104, in review, 2017.
Emmanuel Le Meur et al.
Emmanuel Le Meur et al.
Emmanuel Le Meur et al.

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Short summary
This paper presents surface mass balance measurements from both GPR and ice core data collected during a traverse in a so-far unexplored area between the DC and Vostok stations. Results presented here will contribute to a better knowlegde of the global mass balance of the Antarctic ice sheet and thus help in constraining its contribution to sea level rise. Another novelty of the paper resides in the comprehensive error budget proposed for the method used for infering accumulation rates.
This paper presents surface mass balance measurements from both GPR and ice core data collected...
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