In Situ Sea Ice Stress Data from the SIDEx (Sea Ice Dynamics Experiment) 2021 Beaufort Sea Field Campaign

The Sea Ice Dynamics Experiment (SIDEx) was a field campaign in the Beaufort Sea during February to April 2021. The field experiment was designed to investigate the interaction of ice stress, strain, and fracture over meter-to-kilometer spatial scales as ice fractured and subsequently deformed. Observations were collected in situ at an ice camp, using autonomous buoys, and with remote sensing. Observations were collected over a variety of scales, including scales larger than the target m-km (meter-kilometer) scale. This dataset is one facet of the multi-modal data package collected together in this parent archive. This dataset contains stress observations collected in situ at points across the drifting ice floe from 3 March - 20 April 2021. We deployed an array of 31 Geokon Model 4351 stress gages with Campbell CRW3 data loggers and RF407 radios telemetering data during the SIDEx field experiment in a roughly 3x3 km area. We refer to each of these systems as a “Vibrating Wire Stress Gage” (VWSG) system. Data collection occurred once per minute from sensor deployment beginning March 3 through site recovery on April 20. Sensors were installed such that the vibrating wire rosette would be positioned 25 cm (centimeter) beneath the ice surface, by boring a hole approximately 2 cm larger than the sensor cylinder to the appropriate depth. Sensors were then placed, with the orientation mark either toward magnetic north or toward camp (as noted) and the hole was filled with fresh water, and permitted to freeze. The sensors consist of a rigid steel cylinder with a rosette of three steel wires strung across its hollow interior. During each sample the wires in the rosette are magnetically plucked and the resonant frequency of each wire is recorded by the CRVW3 logger. Strain on the cylinder causes changes in the tension of the vibrating wires and alters their resonant frequency. Primary and secondary principle stresses are calculated using the frequency reading, known material qualities of the sensor itself, and the inclusion factors of the sensor to the ice following the approach of Cox and Johnson 1983 to resolve the stress into primary and secondary principle components and azimuthal angle, relative to true north at 0 degrees. Temperature of the sensor also impacts wire tension and is corrected for using a calibration curve determined from a multi-point calibration of each sensor prior to deployment, as per Geokon’s procedures. A temperature sensor is included in each gage near the rosette. Outputs are presented in primary and secondary principle stress, their angle from true north, and the temperature of the stress gage. Information on the ice thickness and type at the deployment sites is included in a separate file. We use the convention that compressive stresses are positive.