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Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2015

Dartmouth Scholarship

Hydrology

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Impact Of Spatial Aliasing On Sea-Ice Thickness Measurements, Cathleen Geiger, Hans-Reinhard Müller, Jesse P. Samluk, E Rachel Bernstein, Jacqueline Richter-Menge Jan 2015

Impact Of Spatial Aliasing On Sea-Ice Thickness Measurements, Cathleen Geiger, Hans-Reinhard Müller, Jesse P. Samluk, E Rachel Bernstein, Jacqueline Richter-Menge

Dartmouth Scholarship

We explore spatial aliasing of non-Gaussian distributions of sea-ice thickness. Using a heuristic model and >1000 measurements, we show how different instrument footprint sizes and shapes can cluster thickness distributions into artificial modes, thereby distorting frequency distribution, making it difficult to compare and communicate information across spatial scales. This problem has not been dealt with systematically in sea ice until now, largely because it appears to incur no significant change in integrated thickness which often serves as a volume proxy. Concomitantly, demands are increasing for thickness distribution as a resource for modeling, monitoring and forecasting air–sea fluxes and growing human …


On The Uncertainty Of Sea-Ice Isostasy, Cathleen Geiger, Peter Wadhams, Hans-Reinhard Müller, Jacqueline Richter-Menge Jan 2015

On The Uncertainty Of Sea-Ice Isostasy, Cathleen Geiger, Peter Wadhams, Hans-Reinhard Müller, Jacqueline Richter-Menge

Dartmouth Scholarship

During late winter 2007, coincident measurements of sea ice were collected using various sensors at an ice camp in the Beaufort Sea, Canadian Arctic. Analysis of the archived data provides new insight into sea-ice isostasy and its related R-factor through case studies at three scales using different combinations of snow and ice thickness components. At the smallest scale (<1 m; point scale), isostasy is not expected, so we calculate a residual and define this as �� (‘zjey’) to describe vertical displacement due to deformation. From 1 to 10 m length scales, we explore traditional isostasy and identify a specific sequence of thickness calculations which minimize freeboard and elevation uncertainty. An effective solution exists when the R-factor is allowed to vary: ranging from 2 to 12, with mean of 5.17, mode of 5.88 and skewed distribution. At regional scales, underwater, airborne and spaceborne platforms are always missing thickness variables from either above or below sea level. For such situations, realistic agreement is found by applying small-scale skewed ranges for the R-factor. These findings encourage a broader isostasy solution as a function of potential energy and length scale. Overall, results add insight to data collection strategies and metadata characteristics of different thickness products.