Expendable bathythermograph (XBT) data collected along the Southern Ocean chokepoint between Aotearoa / New Zealand and Antarctica, 1994–2024

Abstract. This study presents the water column temperature data collected during several cruises on board the Italica, Araon, and Laura Bassi research vessels in the framework of the Climatic Long-term Interaction for the Mass balance in Antarctica (CLIMA), Southern Ocean Chokepoints Italian Contribution (SOChIC), and Marine Observatory of the Ross Sea (MORSea) projects funded by the Italian National Antarctic Research Program (PNRA). Data were collected between Aotearoa / New Zealand and the Ross Sea during the austral summers from 1994/1995 to 2023/2024. Across this chokepoint of the Antarctic Circumpolar Current, expendable bathythermograph (XBT) Sippican T7 probes were launched with a regular 20 km sampling, providing temperature profiles with a vertical resolution of 65 cm and a maximum nominal depth of 760 m. All temperature profiles underwent rigorous quality control, including a general malfunctioning verification, the removal of spikes, the consistency check of adjacent profiles, the comparison to regional oceanographic features and satellite altimetry observations, and a final visual check by the operator. Data quality checks led us to discard about 12 % of acquired XBT measurements. The full XBT dataset can be accessed as text format files via the following link: https://doi.org/10.5281/zenodo.14848849 (Aulicino et al., 2025). This dataset contributes to the improvement of our understanding of Southern Ocean features, being highly valuable for studies focusing on climate variability, especially across the Antarctic Circumpolar Current and its fronts. Furthermore, we expect that the collected XBT data will serve as a useful tool for the calibration and validation of recent satellite observations and for the improvement of Southern Ocean oceanographic simulations.