Author(s): Chris Petrich; Victoria Bonath
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Abstract: Properties of sea ice are the cumulative result of environmental conditions. We investigate for one particular case to what extent observed ice properties can be related to environmental conditions inferred from large-scale products. Drifting first-year sea ice was investigated in Fram Strait during a ColdTech expedition onboard Norwegian icebreaker KV Svalbard in March 2012. First-year sea ice adjacent to a pressure ridge was investigated. Ice properties investigated at multiple locations include ice thickness and snow depth, sea ice salinity profiles, vertical profiles of sea ice fabric, and block size of the pressure ridge. The salinity profile followed a C-shape typical of first-year sea ice. The ice fabric was mostly columnar with distinct breaks in the crystal profile and localized frazil ice inclusions. An attempt was made to re-create the history of the ice using a drift trajectory derived from the OSI-405 Low Resolution Sea Ice Drift product of met. no. The drift track suggested several periods of deformations and stagnation. Weather data corresponding to the drift track were derived from both NCEP and ERA Interim reanalyses. The relationship between ice thickness and time was inferred from degree-day models, and the salinity profile was reconstructed from a combination of degree-day model and a simple salinity parameterization. Positions of the breaks in crystal structure were inferred from the growth history of the degree-day model in conjunction with drift and deformation events along the reconstructed drift trajectory. Reconstructed ice properties were found to be consistent with observations. However, random errors in measurements and potential systematic errors of reanalyses, models and parameterizations call for a repeat of the analyses based on larger datasets.
Year: 2014