Drift of pancake ice floes in the winter Antarctic marginal ice zone during polar cyclones

Alberello, Alberto, Bennetts, Luke, Heil, Petra, Eayrs, Clare, Vichi, Marcello, MacHutchon, Keith, Onorato, Miguel and Toffoli, Alessandro (2020) Drift of pancake ice floes in the winter Antarctic marginal ice zone during polar cyclones. Journal of Geophysical Research: Oceans, 125 (3). ISSN 2169-9275

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Abstract

High temporal resolution in situ measurements of pancake ice drift are presented, from a pair of buoys deployed on floes in the Antarctic marginal ice zone during the winter sea ice expansion, over 9 days in which the region was impacted by four polar cyclones. Concomitant measurements of wave-in-ice activity from the buoys are used to infer that the ice remained unconsolidated, and pancake ice conditions were maintained over at least the first 7 days. Analysis of the data shows (i) the fastest reported ice drift speeds in the Southern Ocean; (ii) high correlation of drift velocities with the surface wind velocities, indicating absence of internal ice stresses >100 km from the ice edge where remotely sensed ice concentration is 100%; and (iii) presence of a strong inertial signature with a 13 hr period. A Lagrangian free drift model is developed, including a term for geostrophic currents that reproduce the 13 hr period signature in the ice motion. The calibrated model provides accurate predictions of the ice drift for up to 2 days, and the calibrated parameters provide estimates of wind and ocean drag for pancake floes under storm conditions.

Item Type: Article
Additional Information: Funding Information: The expedition was funded by the South African National Antarctic Programme through the National Research Foundation. This work was partially funded by the ACE Foundation and Ferring Pharmaceuticals. A. A., L. B., A. T., and P. H. were supported by the Australian Antarctic Science Program (all by Project 4434 and PH by Projects 4301 and 4390). M. O. was supported by the Departments of Excellence20182022 Grant awarded by the Italian Ministry of Education, University and Research (MIUR) (L.232/2016). C. E. was supported under NYUAD Center for Global Sea Level Change ProjectG1204. P. H. was supported by the Australian Governments Cooperative Research Centres Programme through the Antarctic Climate and Ecosystems Cooperative Research Centre. We are indebted to Captain Knowledge Bengu and the crew of the SA Agulhas II for their invaluable contribution to data collection. We thank the two anonymous reviewers; their comments improved the original submitted manuscript. ERA5 reanalysis was obtained using Copernicus Climate Change Service Information 2019. A. A. and A. T. acknowledge support from the Air‐Sea‐Ice‐Lab Project. M. O. acknowledges B. GiuliNico for interesting discussions. Buoy data are publicly available online ( https://doi.org/10.26179/5cc934992f065 ). Funding Information: The expedition was funded by the South African National Antarctic Programme through the National Research Foundation. This work was partially funded by the ACE Foundation and Ferring Pharmaceuticals. A.?A., L.?B., A.?T., and P.?H. were supported by the Australian Antarctic Science Program (all by Project 4434 and PH by Projects 4301 and 4390). M.?O. was supported by the Departments of Excellence20182022 Grant awarded by the Italian Ministry of Education, University and Research (MIUR) (L.232/2016). C.?E. was supported under NYUAD Center for Global Sea Level Change ProjectG1204. P.?H. was supported by the Australian Governments Cooperative Research Centres Programme through the Antarctic Climate and Ecosystems Cooperative Research Centre. We are indebted to Captain Knowledge Bengu and the crew of the SA Agulhas II for their invaluable contribution to data collection. We thank the two anonymous reviewers; their comments improved the original submitted manuscript. ERA5 reanalysis was obtained using Copernicus Climate Change Service Information 2019. A.?A. and A.?T. acknowledge support from the Air-Sea-Ice-Lab Project. M.?O. acknowledges B. GiuliNico for interesting discussions. Buoy data are publicly available online (https://doi.org/10.26179/5cc934992f065). Publisher Copyright: ©2020. American Geophysical Union. All Rights Reserved.
Uncontrolled Keywords: antarctic,buoy,drift,marginal ice zone,pancake ice,sea ice,geochemistry and petrology,geophysics,earth and planetary sciences (miscellaneous),space and planetary science,oceanography ,/dk/atira/pure/subjectarea/asjc/1900/1906
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Depositing User: LivePure Connector
Date Deposited: 13 Nov 2021 01:51
Last Modified: 02 Dec 2021 02:49
URI: https://ueaeprints.uea.ac.uk/id/eprint/82081
DOI: 10.1029/2019JC015418

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