Megadunes in Antarctica: migration and characterization from remote and in situ observations
<p>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 propertie...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2023-02-01
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| Series: | The Cryosphere |
| Online Access: | https://tc.copernicus.org/articles/17/427/2023/tc-17-427-2023.pdf |
| _version_ | 1797937833990684672 |
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| author | G. Traversa G. Traversa D. Fugazza M. Frezzotti |
| author_facet | G. Traversa G. Traversa D. Fugazza M. Frezzotti |
| author_sort | G. Traversa |
| collection | DOAJ |
| description | <p>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<span class="inline-formula"><sup>−1</sup></span>. 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.</p> |
| first_indexed | 2024-04-10T18:50:28Z |
| format | Article |
| id | doaj.art-82a60b03bb2f4e73ab3192ddacfb1194 |
| institution | Directory Open Access Journal |
| issn | 1994-0416 1994-0424 |
| language | English |
| last_indexed | 2024-04-10T18:50:28Z |
| publishDate | 2023-02-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | The Cryosphere |
| spelling | doaj.art-82a60b03bb2f4e73ab3192ddacfb11942023-02-01T08:01:23ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242023-02-011742744410.5194/tc-17-427-2023Megadunes in Antarctica: migration and characterization from remote and in situ observationsG. Traversa0G. Traversa1D. Fugazza2M. Frezzotti3Institute of Polar Sciences, National Research Council of Italy, 20125 Milan, Italy Department of Physical Sciences, Earth and Environment (DSFTA), Università degli Studi di Siena, 53100 Siena, ItalyDepartment of Environmental Science and Policy (ESP), Università degli Studi di Milano, 20133 Milan, ItalyDepartment of Science, Università degli Studi Roma Tre, 00146 Rome, Italy<p>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<span class="inline-formula"><sup>−1</sup></span>. 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.</p>https://tc.copernicus.org/articles/17/427/2023/tc-17-427-2023.pdf |
| spellingShingle | G. Traversa G. Traversa D. Fugazza M. Frezzotti Megadunes in Antarctica: migration and characterization from remote and in situ observations The Cryosphere |
| title | Megadunes in Antarctica: migration and characterization from remote and in situ observations |
| title_full | Megadunes in Antarctica: migration and characterization from remote and in situ observations |
| title_fullStr | Megadunes in Antarctica: migration and characterization from remote and in situ observations |
| title_full_unstemmed | Megadunes in Antarctica: migration and characterization from remote and in situ observations |
| title_short | Megadunes in Antarctica: migration and characterization from remote and in situ observations |
| title_sort | megadunes in antarctica migration and characterization from remote and in situ observations |
| url | https://tc.copernicus.org/articles/17/427/2023/tc-17-427-2023.pdf |
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