Low Frequency (10 Hz – 95 kHz) Sea Ice Complex Permittivity Measurements

• Format: Dataset
• Language: unknown
• Published: Arctic Data Center
• Subjects: sea ice; complex dielectric permittivity; electric properties; Barrow; Fairbanks; Pacific; ice core; Sea ice; Alaska
• Online Access: https://search.dataone.org/view/a01d96f1-8c13-415f-87c1-9073081dbf5a

Data collected in March, May, and June of 2013 and 2014 to capture seasonal evolution of low frequency electric properties of natural sea ice. Values for the real and imaginary parts of the complex permittivity are derived from measurements of impedance and phase. To obtain these measurements, four electrode strings, 2.0 m long and composed of steel washers positioned at 0.1 m increments, were installed vertically in the sea ice at the corners of a 1 m x 1 m square. Installation occurred in early January to allow adequate time for ice to regrow before measurements were collected. Measurements were gathered through injecting and removing current at two selected electrodes. Voltage was simultaneously measured at two additional electrodes and the potential difference between the two determined. Impedance is defined as the ratio of these two values while phase provides a measurement of lag between the current and voltage waveforms. From these measurements, complex permittivity was calculated. The data presented here show permittivity at a specific depth. To obtain measurements at 0.15 m, a current was injected and removed at 0.10 m and potential difference measured between electrodes placed at 0.20 m. This combination was then reversed with current being injected and removed at 0.20 m and potential difference measured at 0.10 m. For one depth, this routine was repeated for each of the 6 pairs of electrode strings. Each value of permittivity at a given frequency, depth, and date therefore represents the mean, and related standard deviation, of upwards of 12 measurements. Ice core measurements, including ice temperature and bulk salinity, gathered in parallel to complex permittivity measurements 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 data presented here was 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.