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Seasonal evolution of an ice-shelf influenced fast-ice regime, derived from an autonomous thermistor chain
Citation
Hoppmann, M and Nicolaus, M and Hunkeler, PA and Heil, P and Behrens, L-K and Konig-Langlo, G and Gerdes, R, Seasonal evolution of an ice-shelf influenced fast-ice regime, derived from an autonomous thermistor chain, Journal of Geophysical Research: Oceans, 120, (3) pp. 1703-1724. ISSN 2169-9275 (2015) [Refereed Article]
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Copyright Statement
Copyright 2015 The Authors
Abstract
Ice shelves strongly interact with coastal Antarctic sea ice and the associated ecosystem by creating conditions favorable to the formation of a sub-ice platelet layer. The close investigation of this phenomenon and its seasonal evolution remains a challenge due to logistical constraints and a lack of suitable methodology. In this study, we characterize the seasonal cycle of Antarctic fast ice adjacent to the Ekström Ice Shelf in the eastern Weddell Sea. We used a thermistor chain with the additional ability to record the temperature response induced by cyclic heating of resistors embedded in the chain. Vertical sea-ice temperature and heating profiles obtained daily between November 2012 and February 2014 were analyzed to determine sea-ice and snow evolution, and to calculate the basal energy budget. The residual heat flux translated into an ice-volume fraction in the platelet layer of 0.18 ± 0.09, which we reproduced by a independent model simulation and agrees with earlier results. Manual drillings revealed an average annual platelet-layer thickness increase of at least 4 m, and an annual maximum thickness of 10 m beneath second-year sea ice. The oceanic contribution dominated the total sea-ice production during the study, effectively accounting for up to 70% of second-year sea-ice growth. In summer, an oceanic heat flux of 21 W m−2 led to a partial thinning of the platelet layer. Our results further show that the active heating method, in contrast to the acoustic sounding approach, is well suited to derive the fast-ice mass balance in regions influenced by ocean/ice-shelf interaction, as it allows subdiurnal monitoring of the platelet-layer thickness.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | Antarctic sea ice, ice shelves, sub-ice platelet layer, Antarctic fast ice |
| Research Division: | Earth Sciences |
| Research Group: | Physical geography and environmental geoscience |
| Research Field: | Glaciology |
| Objective Division: | Expanding Knowledge |
| Objective Group: | Expanding knowledge |
| Objective Field: | Expanding knowledge in the earth sciences |
| UTAS Author: | Heil, P (Dr Petra Heil) |
| ID Code: | 100206 |
| Year Published: | 2015 |
| Web of Science® Times Cited: | 31 |
| Deposited By: | CRC-Antarctic Climate & Ecosystems |
| Deposited On: | 2015-05-07 |
| Last Modified: | 2017-10-30 |
| Downloads: | 302 View Download Statistics |
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