Physical and chemical oceanographic data during Umitaka-maru cruise of the 64th Japanese Antarctic Research Expedition in January 2023

The Southern Ocean connects all major ocean basins and plays a pivotal role in the meridional overturning circulation of the global oceans. High-quality physical (temperature, salinity, and dissolved oxygen) and chemical (nutrients) oceanographic data from the Southern Ocean are thus critical for an improved understanding of future climates. As part of the 64th Japanese Antarctic Research Expedition, and also as a part of annually conducted monitoring observations, we have obtained high-quality Conductivity-Temperature-Depth (CTD) and water sampling data (salinity, dissolved oxygen, and nutrients) at 9 sites located along a 110E transect in January 2023. Sea surface temperature and salinity were obtained continuously with a thermosalinograph (TSG) along the cruise track between the ports of Fremantle and Hobart, except within the Australian Exclusive Economic Zone. Data quality was validated by following as far as possible the recommendations for instruments and methods of the Global Ocean Ship-Based Hydrographic Investigation Program.南大洋连通所有主要大洋盆地，在全球大洋经向翻转环流中发挥着核心作用。因此，获取南大洋高质量的物理海洋学（温度、盐度与溶解氧）及化学海洋学（营养盐）观测数据，对于深化未来气候认知至关重要。本数据集作为第64次日本南极考察（64th Japanese Antarctic Research Expedition）的组成部分，同时纳入年度常规监测观测项目。研究团队于2023年1月在沿110°E断面的9个站位，采集了高质量的温盐深剖面仪（Conductivity-Temperature-Depth, CTD）测量数据与水样数据，涵盖盐度、溶解氧及营养盐指标。此外，研究团队在弗里曼特尔与霍巴特港之间的航行航线上，通过海表温盐计（thermosalinograph, TSG）连续获取海表温度与盐度数据，澳大利亚专属经济区（Australian Exclusive Economic Zone）海域除外。所有数据均尽可能遵循全球海洋船舶水文调查计划（Global Ocean Ship-Based Hydrographic Investigation Program）的仪器操作与方法相关建议完成了质量验证。