Megadunes in Antarctica: migration and characterization from remote and in situ observations
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Published:2023-02-01
Issue:1
Volume:17
Page:427-444
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ISSN:1994-0424
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Container-title:The Cryosphere
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language:en
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Short-container-title:The Cryosphere
Author:
Traversa Giacomo, Fugazza DavideORCID, Frezzotti MassimoORCID
Abstract
Abstract. Megadunes are peculiar features formed by the interaction between
the atmosphere and cryosphere and are known to be present only on the East
Antarctic Plateau and other planets (Mars and Pluto). In this study, we have
analysed the glaciological dynamic of megadunes, their spectral properties
and morphology on two sample areas of the East Antarctic Plateau where in
the past international field activities were carried out (EAIIST, East Antarctic International Ice Sheet Traverse;
It-ITASE, Italian International Trans-Antarctic Scientific Expedition). Using satellite images spanning 7 years, we analysed the spatial
and temporal variability in megadune surface characteristics, i.e. near-infrared (NIR) albedo, thermal brightness temperature (BT) and slope along
the prevailing wind direction (SPWD), useful for mapping them. These
parameters allowed us to characterize and perform an automated detection of
the glazed surfaces, and we determined the influence of the SPWD by
evaluating different combinations of these parameters. The inclusion of the
SPWD significantly increased the accuracy of the method, doubling it in
certain analysed scenes. Using remote and field observations, for the first
time we surveyed all the components of upwind migration (absolute,
sedimentological and ice flow), finding an absolute value of about 10 m a−1. The analysis shows that the migration is driven by the snow
accumulation on the crest and trough prograding upwind on the previous
windward flanks characterized by glazed surface. Our results present
significant implications for the surface mass balance estimation, paleo-climate
reconstruction using ice cores, and the measurements using optical and
radar images/data in the megadune areas.
Publisher
Copernicus GmbH
Subject
Earth-Surface Processes,Water Science and Technology
Reference56 articles.
1. Agosta, C., Amory, C., Kittel, C., Orsi, A., Favier, V., Gallée, H., van den Broeke, M. R., Lenaerts, J. T. M., van Wessem, J. M., van de Berg, W. J., and Fettweis, X.: Estimation of the Antarctic surface mass balance using the regional climate model MAR (1979–2015) and identification of dominant processes, The Cryosphere, 13, 281–296, https://doi.org/10.5194/tc-13-281-2019, 2019. 2. Albert, M., Shuman, C., Courville, Z., Bauer, R., Fahnestock, M., and
Scambos, T.: Extreme firn metamorphism: impact of decades of vapor transport
on near-surface firn at a low-accumulation glazed site on the East Antarctic
plateau, Ann. Glaciol., 39, 73–78,
https://doi.org/10.3189/172756404781814041, 2004. 3. Arcone, S. A., Jacobel, R., and Hamilton, G.: Unconformable stratigraphy in
East Antarctica: Part I. Large firn cosets, recrystallized growth, and model
evidence for intensified accumulation, J. Glaciol., 58, 240–252,
https://doi.org/10.3189/2012JoJ11J044, 2012a. 4. Arcone, S. A., Jacobel, R., and Hamilton, G.: Unconformable stratigraphy in
East Antarctica: Part II. Englacial cosets and recrystallized layers, J.
Glaciol., 58, 253–264, https://doi.org/10.3189/2012JoG11J045, 2012b. 5. Azzoni, R. S., Senese, A., Zerboni, A., Maugeri, M., Smiraglia, C., and Diolaiuti, G. A.: Estimating ice albedo from fine debris cover quantified by a semi-automatic method: the case study of Forni Glacier, Italian Alps, The Cryosphere, 10, 665–679, https://doi.org/10.5194/tc-10-665-2016, 2016.
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