Brief data description A Trident Sensors Helix Beacon identical to the one described in Womack et al. (2022), was deployed on sea ice at latitude 59.47o S and longitude 10.89o E, on 30 October 2019, as part of the Southern oCean seAsonal Experiment (SCALE; Ryan-Keogh and Vichi, 2022) aboard the SA Agulhas II. The region where the Trident was deployed (Antarctic marginal ice zone) consisted of first-year ice conditions, with an average thickness of 80-90 cm. The device was deployed by hand by three people, lowered by crane from the ship to the ice on a basket cradle. The temporal resolution was approximately four hours. The survival of the Trident depended on staying fixed to the ice floe and its battery life. The Trident recorded GPS position and air temperature, and transmitted data until 2 December 2019, where it sank due to sea-ice melting. Buoy name and raw data: Trident: Unit4.xlsx Related code: The buoy data has been processed using https://github.com/mvichi/antarctic-buoys/.

This research has been supported by the National Research Foundation of South Africa (grant no. 118745). This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement no. 101003826 via project CRiceS (Climate Relevant interactions and feedbacks: the key role of sea ice and Snow in the polar and global climate system). A.T. acknowledges the support from the Australian Research Council (DP200102828). A.A acknowledges the support from the London Mathematical Society (Scheme 5 – Ref. 52206). We acknowledge the Southern oCean seAsonaL Experiment (SCALE), and thank the captain and the crew of the SA Agulhas II for the assistance during the deployments.

{"references": ["Ryan-Keogh, T. and Vichi, M. (2022). SCALE-WIN19 & SCALE-SPR19 Cruise Report, Southern Ocean Seasonal Cycle Experiment, South Africa, 339 pp,\u00a0 https://doi.org/10.5281/zenodo.5906324.", "Womack, A., Vichi, M., Alberello, A., and Toffoli, A. (2022). Atmospheric drivers of a winter-to-spring Lagrangian sea-ice drift in the Eastern Antarctic marginal ice zone.\u00a0Journal of Glaciology, 1-15. https://doi.org/10.1017/jog.2022.14."]}