A quasi-objective single buoy approach for Lagrangian coherent structures and sea ice fracture events

Sea ice deformation and dynamics play a significant role in atmosphere-ice-ocean coupling. Deformation patterns in sea ice can be observed at a wide range of spatial scales, though high resolution objective quantification of these features remains difficult. In an effort to better understand local d...

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Bibliographic Details
Main Authors: Aksamit, Nikolas O., Scharien, Randall K., Hutchings, Jennifer K.
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2022
Subjects:
Online Access:https://doi.org/10.5194/egusphere-2022-519
https://noa.gwlb.de/receive/cop_mods_00062353
https://egusphere.copernicus.org/preprints/egusphere-2022-519/egusphere-2022-519.pdf
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Summary:Sea ice deformation and dynamics play a significant role in atmosphere-ice-ocean coupling. Deformation patterns in sea ice can be observed at a wide range of spatial scales, though high resolution objective quantification of these features remains difficult. In an effort to better understand local deformation of sea ice, we adapt the Trajectory Stretching Exponents (TSEs), quasi-objective measures of Lagrangian stretching in continuous media, to sea ice buoy data, and develop a temporal analysis of TSE time series. TSEs provide an approximation of Lagrangian coherent structure diagnostics when only sparse trajectory data is available. As TSEs do not require multiple buoys, we find they have an expanded range of use when compared with traditional Eulerian buoy-array deformation metrics, and provide local-stretching information below the length-scales possible when averaging over buoy-arrays. We verify the ability of TSEs to temporally and spatially identify dynamic fracture events for three different sea ice datasets, with buoys identifying fracture domains ranging tens to hundreds of kilometers in diameter.