Comparisons of Sea-Ice Velocity Fields from ERS-1 SAR and a dynamic model
Abstract Numerical models for sea-ice thickness distribution and velocity are used for ice-dynamics research and ice forecasting. In the modeling work, ERS-1 SAR is an excellent tool, in particular by providing spatial ice-velocity fields as described in the present Baltic Sea study. Ice velocities...
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Cambridge University Press (CUP)
1998
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Online Access: | http://dx.doi.org/10.1017/s0022143000002598 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000002598 |
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crcambridgeupr:10.1017/s0022143000002598 2024-06-23T07:53:44+00:00 Comparisons of Sea-Ice Velocity Fields from ERS-1 SAR and a dynamic model Leppäranta, Matti Sun, Yan Haapala, Jari 1998 http://dx.doi.org/10.1017/s0022143000002598 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000002598 en eng Cambridge University Press (CUP) Journal of Glaciology volume 44, issue 147, page 248-262 ISSN 0022-1430 1727-5652 journal-article 1998 crcambridgeupr https://doi.org/10.1017/s0022143000002598 2024-06-12T04:04:55Z Abstract Numerical models for sea-ice thickness distribution and velocity are used for ice-dynamics research and ice forecasting. In the modeling work, ERS-1 SAR is an excellent tool, in particular by providing spatial ice-velocity fields as described in the present Baltic Sea study. Ice velocities were extracted from SAR data with 3 and 6 day time intervals using the optical-flow method. A considerable stiffening of the ice pack was observed due to the change in the character of ice déformation under compression from rafting to ridging as the minimum ice thickness increased from 10 to 3O cm. The coastal alignment was strong in the ice motion and the coastal boundary layer width was 20-30 km. An analysis of the SAR data with an ice-dynamics model showed that the observed overall ice-velocity field could be produred using the Hibler viscous-plastic ice rheology. The compressive strength of the ice (over 10 km sc ales) was 2.5x 10 4 N m −2 ±50% for ridging and negligible for rafting of very thin ice. The shear strength was significant and the normal yield ellipse aspect ratio of 2 was valid. The 3 day time interval is val id for updating an ice model but for detailed ice-dynamics investigations a data frequency of 1 d −1 or higher would be preferable. Article in Journal/Newspaper ice pack Journal of Glaciology Sea ice Cambridge University Press Journal of Glaciology 44 147 248 262 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
description |
Abstract Numerical models for sea-ice thickness distribution and velocity are used for ice-dynamics research and ice forecasting. In the modeling work, ERS-1 SAR is an excellent tool, in particular by providing spatial ice-velocity fields as described in the present Baltic Sea study. Ice velocities were extracted from SAR data with 3 and 6 day time intervals using the optical-flow method. A considerable stiffening of the ice pack was observed due to the change in the character of ice déformation under compression from rafting to ridging as the minimum ice thickness increased from 10 to 3O cm. The coastal alignment was strong in the ice motion and the coastal boundary layer width was 20-30 km. An analysis of the SAR data with an ice-dynamics model showed that the observed overall ice-velocity field could be produred using the Hibler viscous-plastic ice rheology. The compressive strength of the ice (over 10 km sc ales) was 2.5x 10 4 N m −2 ±50% for ridging and negligible for rafting of very thin ice. The shear strength was significant and the normal yield ellipse aspect ratio of 2 was valid. The 3 day time interval is val id for updating an ice model but for detailed ice-dynamics investigations a data frequency of 1 d −1 or higher would be preferable. |
format |
Article in Journal/Newspaper |
author |
Leppäranta, Matti Sun, Yan Haapala, Jari |
spellingShingle |
Leppäranta, Matti Sun, Yan Haapala, Jari Comparisons of Sea-Ice Velocity Fields from ERS-1 SAR and a dynamic model |
author_facet |
Leppäranta, Matti Sun, Yan Haapala, Jari |
author_sort |
Leppäranta, Matti |
title |
Comparisons of Sea-Ice Velocity Fields from ERS-1 SAR and a dynamic model |
title_short |
Comparisons of Sea-Ice Velocity Fields from ERS-1 SAR and a dynamic model |
title_full |
Comparisons of Sea-Ice Velocity Fields from ERS-1 SAR and a dynamic model |
title_fullStr |
Comparisons of Sea-Ice Velocity Fields from ERS-1 SAR and a dynamic model |
title_full_unstemmed |
Comparisons of Sea-Ice Velocity Fields from ERS-1 SAR and a dynamic model |
title_sort |
comparisons of sea-ice velocity fields from ers-1 sar and a dynamic model |
publisher |
Cambridge University Press (CUP) |
publishDate |
1998 |
url |
http://dx.doi.org/10.1017/s0022143000002598 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000002598 |
genre |
ice pack Journal of Glaciology Sea ice |
genre_facet |
ice pack Journal of Glaciology Sea ice |
op_source |
Journal of Glaciology volume 44, issue 147, page 248-262 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000002598 |
container_title |
Journal of Glaciology |
container_volume |
44 |
container_issue |
147 |
container_start_page |
248 |
op_container_end_page |
262 |
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1802645535416385536 |