| Summary: | Natural sea ice samples gathered from land fast sea ice located off the coast of Barrow, Alaska in 2013 and 2014. All samples were centrifuged before being transported to the Geophysical Institute Sea Ice Laboratory located in Fairbanks, AK. To image, sample cylinders 50 mm in length and 30 mm in diameter were produced using a bandsaw and lathe held in a cold room set to a temperatures between -10 and -15 degrees C. A Skyscan 1074 portable micro-CT scanner held in chamber with a temperature of -20 degrees C was used for X-Ray CT imaging. The scanner was initially calibrated to ensure the x-ray tube was performing well, the stage where the sample is place was centered, and to gather a flat field image for the given voltage, current, and exposure. Individual vertical projection images were gathered at 0.90° increments over ~180° totaling 201 projections for each sample. These images of a 16-bit TIFF format with pixels 40 microns in size, were reconstructed using NRecon software (Bruker microCT, Kontich, Belgium) to create a 3D volumetric stack of 8-bit JPEG images. Each resultant image represents a horizontal 'slice' of the volume, 40 microns in thickness. Ice core measurements, including ice temperature and bulk salinity, gathered in parallel to imaged samples can be found at: https://arcticdata.io/catalog/#view/doi:10.18739/A2KQ0P . Measurements of air temperature, snow depth, and ice thickness, gathered at the UAF Sea Ice mass balance site in Barrow, AK can be found at: https://arcticdata.io/catalog/#view/doi:10.18739/A2D08X . Funding for data collection and analysis was provided by the National Science Foundation CMG Program (OPP-0934683) supplemented by support from the SIZONet Project (OPP-0856867) and the East Asia and Pacific Summer Institutes Program (EAPSI). Processing and analysis of the images presented here were completed as part of the University of Alaska Fairbanks MSc thesis of Megan O'Sadnick titled 'In-situ monitoring of sea ice dielectric properties and implications for the tracking of seasonal evolution of microstructure'. A scientific journal article summarizing the most pertinent results is available at: http://www.the-cryosphere.net/10/2923/2016/. Citation: O'Sadnick, M., Ingham, M., Eicken, H., and Pettit, E.: In situ field measurements of the temporal evolution of low-frequency sea-ice dielectric properties in relation to temperature, salinity, and microstructure, The Cryosphere, 10, 2923-2940, doi:10.5194/tc-10-2923-2016, 2016.
|
|---|