Evaluation of ship-based electromagnetic-inductive thickness measurements of summer sea-ice in the Bellingshausen and Amundsen Seas, Antarctica
The accuracy of electromagnetic-inductive (EM) sea-ice thickness measure-ments performed from a moving icebreaker is evaluated. Ice thickness distributions and ridge statistics are derived. In the Bellingshausen Sea the ice was moderately deformed with mean and modal ice thicknesses of 1.3 and 0.9 m...
Main Author: | |
---|---|
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
1998
|
Subjects: | |
Online Access: | https://epic.awi.de/id/eprint/1142/ https://epic.awi.de/id/eprint/1142/1/Haa1998a.pdf https://hdl.handle.net/10013/epic.11731 https://hdl.handle.net/10013/epic.11731.d001 |
id |
ftawi:oai:epic.awi.de:1142 |
---|---|
record_format |
openpolar |
spelling |
ftawi:oai:epic.awi.de:1142 2024-09-15T17:39:11+00:00 Evaluation of ship-based electromagnetic-inductive thickness measurements of summer sea-ice in the Bellingshausen and Amundsen Seas, Antarctica Haas, Christian 1998 application/pdf https://epic.awi.de/id/eprint/1142/ https://epic.awi.de/id/eprint/1142/1/Haa1998a.pdf https://hdl.handle.net/10013/epic.11731 https://hdl.handle.net/10013/epic.11731.d001 unknown https://epic.awi.de/id/eprint/1142/1/Haa1998a.pdf https://hdl.handle.net/10013/epic.11731.d001 Haas, C. orcid:0000-0002-7674-3500 (1998) Evaluation of ship-based electromagnetic-inductive thickness measurements of summer sea-ice in the Bellingshausen and Amundsen Seas, Antarctica , Cold Regions Science and Technology, 27 , pp. 1-16 . hdl:10013/epic.11731 EPIC3Cold Regions Science and Technology, 27, pp. 1-16 Article isiRev 1998 ftawi 2024-06-24T03:53:34Z The accuracy of electromagnetic-inductive (EM) sea-ice thickness measure-ments performed from a moving icebreaker is evaluated. Ice thickness distributions and ridge statistics are derived. In the Bellingshausen Sea the ice was moderately deformed with mean and modal ice thicknesses of 1.3 and 0.9 m, respectively. In contrast, the heavily deformed ice in the Amundsen Sea had mean thicknesses between 2.3 and 3.1 m, with modes between 1.6 and 2.7 m. By means of the measured apparent electrical conductivity on ice of known thickness, the conduc-tivity of the perennial summer ice was found to be significant and could not be neglected in the calibration of EM measurements. The high conductivity is mainly due to the widespread occurence of seawater-filled gaps close to the ice surface.The system, consisting of commercially available instruments, yielded reliable mean thickness estimates. This is shown by comparison with drill-hole measurements and visual observations. However, the thickness profiles appear highly low-pass filtered compared to their surface height profile determined with a laser altimeter. Thus the system possesses a limited lateral resolution such that the thickness of single pressure ridges cannot be resolved. This is only in part attributed to the trade-off between increasing instrument height and decreasing lateral resolution of EM measurements. The low resolution is mainly due to the particular EM instrument, as its sensitivity is highly reduced if used far above the water surface, and it has a comparatively long time constant of 1 s. Additionally, the water-filled gap in the ice generally reduces the sensitivity of the measured apparent conductivity to ice thickness changes. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctica Bellingshausen Sea Icebreaker Sea ice Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
institution |
Open Polar |
collection |
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
The accuracy of electromagnetic-inductive (EM) sea-ice thickness measure-ments performed from a moving icebreaker is evaluated. Ice thickness distributions and ridge statistics are derived. In the Bellingshausen Sea the ice was moderately deformed with mean and modal ice thicknesses of 1.3 and 0.9 m, respectively. In contrast, the heavily deformed ice in the Amundsen Sea had mean thicknesses between 2.3 and 3.1 m, with modes between 1.6 and 2.7 m. By means of the measured apparent electrical conductivity on ice of known thickness, the conduc-tivity of the perennial summer ice was found to be significant and could not be neglected in the calibration of EM measurements. The high conductivity is mainly due to the widespread occurence of seawater-filled gaps close to the ice surface.The system, consisting of commercially available instruments, yielded reliable mean thickness estimates. This is shown by comparison with drill-hole measurements and visual observations. However, the thickness profiles appear highly low-pass filtered compared to their surface height profile determined with a laser altimeter. Thus the system possesses a limited lateral resolution such that the thickness of single pressure ridges cannot be resolved. This is only in part attributed to the trade-off between increasing instrument height and decreasing lateral resolution of EM measurements. The low resolution is mainly due to the particular EM instrument, as its sensitivity is highly reduced if used far above the water surface, and it has a comparatively long time constant of 1 s. Additionally, the water-filled gap in the ice generally reduces the sensitivity of the measured apparent conductivity to ice thickness changes. |
format |
Article in Journal/Newspaper |
author |
Haas, Christian |
spellingShingle |
Haas, Christian Evaluation of ship-based electromagnetic-inductive thickness measurements of summer sea-ice in the Bellingshausen and Amundsen Seas, Antarctica |
author_facet |
Haas, Christian |
author_sort |
Haas, Christian |
title |
Evaluation of ship-based electromagnetic-inductive thickness measurements of summer sea-ice in the Bellingshausen and Amundsen Seas, Antarctica |
title_short |
Evaluation of ship-based electromagnetic-inductive thickness measurements of summer sea-ice in the Bellingshausen and Amundsen Seas, Antarctica |
title_full |
Evaluation of ship-based electromagnetic-inductive thickness measurements of summer sea-ice in the Bellingshausen and Amundsen Seas, Antarctica |
title_fullStr |
Evaluation of ship-based electromagnetic-inductive thickness measurements of summer sea-ice in the Bellingshausen and Amundsen Seas, Antarctica |
title_full_unstemmed |
Evaluation of ship-based electromagnetic-inductive thickness measurements of summer sea-ice in the Bellingshausen and Amundsen Seas, Antarctica |
title_sort |
evaluation of ship-based electromagnetic-inductive thickness measurements of summer sea-ice in the bellingshausen and amundsen seas, antarctica |
publishDate |
1998 |
url |
https://epic.awi.de/id/eprint/1142/ https://epic.awi.de/id/eprint/1142/1/Haa1998a.pdf https://hdl.handle.net/10013/epic.11731 https://hdl.handle.net/10013/epic.11731.d001 |
genre |
Amundsen Sea Antarc* Antarctica Bellingshausen Sea Icebreaker Sea ice |
genre_facet |
Amundsen Sea Antarc* Antarctica Bellingshausen Sea Icebreaker Sea ice |
op_source |
EPIC3Cold Regions Science and Technology, 27, pp. 1-16 |
op_relation |
https://epic.awi.de/id/eprint/1142/1/Haa1998a.pdf https://hdl.handle.net/10013/epic.11731.d001 Haas, C. orcid:0000-0002-7674-3500 (1998) Evaluation of ship-based electromagnetic-inductive thickness measurements of summer sea-ice in the Bellingshausen and Amundsen Seas, Antarctica , Cold Regions Science and Technology, 27 , pp. 1-16 . hdl:10013/epic.11731 |
_version_ |
1810477969689280512 |