DOI: 10.5194/tc-15-2167-2021
论文题名: Linking sea ice deformation to ice thickness redistribution using high-resolution satellite and airborne observations
作者: Von Albedyll L. ; Haas C. ; Dierking W.
刊名: Cryosphere
ISSN: 19940416
出版年: 2021
卷: 15, 期: 5 起始页码: 2167
结束页码: 2186
语种: 英语
英文关键词: airborne survey
; deformation
; electromagnetic method
; experimental study
; freezing
; ice thickness
; observatory
; polynya
; radar imagery
; satellite altimetry
; sea ice
; spectral resolution
; synthetic aperture radar
; thermodynamics
; trajectory
英文摘要: An unusual, large, latent-heat polynya opened and then closed by freezing and convergence north of Greenland's coast in late winter 2018. The closing presented a natural but well-constrained full-scale ice deformation experiment. We observed the closing of and deformation within the polynya with satellite synthetic-aperture radar (SAR) imagery and measured the accumulated effects of dynamic and thermodynamic ice growth with an airborne electromagnetic (AEM) ice thickness survey 1 month after the closing began. During that time, strong ice convergence decreased the area of the refrozen polynya by a factor of 2.5. The AEM survey showed mean and modal thicknesses of the 1-month-old ice of 1.96±1.5m and 1.1 m, respectively. We show that this is in close agreement with modeled thermodynamic growth and with the dynamic thickening expected from the polynya area decrease during that time. We found significant differences in the shapes of ice thickness distributions (ITDs) in different regions of the refrozen polynya. These closely corresponded to different deformation histories of the surveyed ice that we reconstructed from Lagrangian ice drift trajectories in reverse chronological order. We constructed the ice drift trajectories from regularly gridded, high-resolution drift fields calculated from SAR imagery and extracted deformation derived from the drift fields along the trajectories. Results show a linear proportionality between convergence and thickness change that agrees well with the ice thickness redistribution theory. We found a proportionality between the e folding of the ITDs' tails and the total deformation experienced by the ice. Lastly, we developed a simple, volumeconserving model to derive dynamic ice thickness change from the combination of Lagrangian trajectories and highresolution SAR drift and deformation fields. The model has a spatial resolution of 1.4 km and reconstructs thickness profiles in reasonable agreement with the AEM observations. The modeled ITD resembles the main characteristics of the observed ITD, including mode, e folding, and full width at half maximum. Thus, we demonstrate that high-resolution SAR deformation observations are capable of producing realistic ice thickness distributions. © 2021 EDP Sciences. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164827
Appears in Collections: 气候变化与战略
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作者单位: Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, 27570, Germany; Institute of Environmental Physics, University of Bremen, Bremen, 28359, Germany; Center for Integrated Remote Sensing and Forecasting for Arctic Operations, UiT-The Arctic University of Norway, Tromsø, 9019, Norway
Recommended Citation:
Von Albedyll L.,Haas C.,Dierking W.. Linking sea ice deformation to ice thickness redistribution using high-resolution satellite and airborne observations[J]. Cryosphere,2021-01-01,15(5)