Seawater temperature profiles from Expendable Bathythermograph (XBT) probe deployments during the Antarctic Circumnavigation Expedition (ACE)

<strong>Dataset abstract</strong> This data set contains vertical seawater temperature profiles measured by Expendable Bathythermograph (XBT) probes that were deployed in the Southern Ocean during the Antarctic Circumnavigation Expedition (ACE) on board the R/V Akademik Tryoshnikov. 40 XBT probes were deployed during legs 2 and 3 of the expedition in the period 25th January, 2017 to 17th March, 2017. The XBT probes are manufactured and distributed by T.S.K./Sippican Tsurumi-Seiki Co. Ltd., Yokohama, Japan (http://www.tsk-jp.com) and are of the type T-07, which is rated at a ship speed of up to 15 knots. These probes have a measuring time of 123 seconds and maximum measurement depth of about 789 m. Probes were launched from a handheld device from the stern of the ship either on the port or starboard side while the ship was moving. The deck unit recorded the temperature and the time since the probe was launched. This time was then converted to depth using the known fall rate of the probe in seawater and the coefficients provided by the manufacturer (WMO standards; Hanawa et al., 1995). The profiles were corrected for known surface biases (Kizu and Hanawa, 2002; Uehara et al., 2008). We provide the raw data, the data produced by using the coefficients provided by the manufacturer, and a corrected version in which we apply an empirical correction based on a comparison with CTD data (Henry et al., 2019), where XBT profiles were launched alongside the CTD deployment. The data has been quality controlled by comparing it to a number of CTD profiles. Data is provided at full vertical resolution and a 1-m averaged resolution. In addition, we provide derived variables such as surface mixed layer depth (temperature threshold) estimates. We are grateful to the crew of the R/V Akademik Tryoshnikov and AARI for donating these probes to our project. Their use-by date had expired, however this was not seen as an issue. This data set provides insights into the hydrography of the Southern Ocean during one austral summer season and complements the CTD temperature profiles measured during ACE by filling in the gaps between CTD stations. <strong>Dataset contents</strong> Data: ace_xbt_raw/ace_xbt_YYYYMMDD_xxxx_uuuuuuuuuuuu.RAW, data file, comma-separated values ace_xbt_wmo_hanawa95_fullres/ace_xbt_YYYYMMDD_xxxx_uuuuuuuuuuuu.XBT, data file, comma-separated values ace_xbt_wmo_hanawa95_1m/ace_xbt_YYYYMMDD_xxxx_uuuuuuuuuuuu_1m.XBT, data file, comma-separated values ace_xbt_corrected_fullres/ace_xbt_YYYYMMDD_xxxx_uuuuuuuuuuuu.XBT, data file, comma-separated values ace_xbt_corrected_1m/ace_xbt_YYYYMMDD_xxxx_uuuuuuuuuuuu_1m.XBT, data file, comma-separated values Auxiliary data: ace_xbt_mld_tavg.csv, data file, comma-separated values ace_merged_ctd_xbt_mld_tsavg.csv, data file, comma-separated values Figures: figure1.pdf, metadata, portable document format ace_xbt_figures/ace_xbt_YYYYMMDD_xxxx_1m.pdf, metadata, portable document format Metadata: ace_xbt_deployment_summary.csv, metadata, comma-separated values data_file_header.txt, metadata, text README.txt, metadata, text <strong>Dataset license</strong> This seawater temperature profile dataset from ACE is made available under the Creative Commons Attribution 4.0 International License (CC BY 4.0) whose full text can be found at https://creativecommons.org/licenses/by/4.0/数据集摘要 本数据集包含由投弃式海水温度剖面仪（Expendable Bathythermograph, XBT）获取的垂直海水温度剖面数据，此类剖面仪在南极环极航行探险队（Antarctic Circumnavigation Expedition, ACE）期间部署于南大洋，搭载平台为科考调查船（Research Vessel, R/V）Akademik Tryoshnikov号。本次探险任务的第2、3航段于2017年1月25日至2017年3月17日期间共部署40台XBT剖面仪。该型号剖面仪由日本横滨的T.S.K./Sippican Tsurumi-Seiki Co. Ltd.制造并分销（官网：http://www.tsk-jp.com），具体型号为T-07，适配的最大航速可达15节。此类剖面仪单次测量时长为123秒，最大测量深度约789米。剖面仪由船员在航行过程中通过手持设备从船尾左舷或右舷投放。甲板单元会记录剖面仪投放后的温度与时长数据，随后依据已知的剖面仪在海水中的下沉速率及制造商提供的系数（符合世界气象组织（World Meteorological Organization, WMO）标准；Hanawa等，1995），将记录的时长转换为对应水深。此外，研究团队已针对已知的表层偏差对剖面数据进行校正（Kizu与Hanawa，2002；Uehara等，2008）。本数据集提供三类数据：原始采集数据、采用制造商提供系数生成的处理数据，以及基于与温盐深仪（Conductivity-Temperature-Depth, CTD）数据对比得到的经验校正版本数据（Henry等，2019），该校正方法适用于与CTD同步投放的XBT剖面。数据集已通过与多组CTD剖面数据对比完成质量控制。数据以全垂直分辨率及1米平均分辨率两种形式提供。此外，数据集还包含衍生变量数据，例如基于温度阈值计算的表层混合层深度估算值。本研究感谢R/V Akademik Tryoshnikov号船员及俄罗斯北极与南极研究所（Arctic and Antarctic Research Institute, AARI）为本项目提供这批剖面仪，尽管这批剖面仪已过保质期，但未对实验造成影响。本数据集可为南大洋在某一南极夏季的水文特征提供研究依据，并通过填补CTD站位间的空白，补充了ACE任务期间获取的CTD温度剖面数据。 数据集内容 数据文件： ace_xbt_raw/ace_xbt_YYYYMMDD_xxxx_uuuuuuuuuuuu.RAW：逗号分隔值（CSV）格式原始数据文件 ace_xbt_wmo_hanawa95_fullres/ace_xbt_YYYYMMDD_xxxx_uuuuuuuuuuuu.XBT：逗号分隔值（CSV）格式，采用WMO标准及Hanawa等1995年系数处理的全分辨率数据文件 ace_xbt_wmo_hanawa95_1m/ace_xbt_YYYYMMDD_xxxx_uuuuuuuuuuuu_1m.XBT：逗号分隔值（CSV）格式，采用WMO标准及Hanawa等1995年系数处理的1米平均分辨率数据文件 ace_xbt_corrected_fullres/ace_xbt_YYYYMMDD_xxxx_uuuuuuuuuuuu.XBT：逗号分隔值（CSV）格式，经经验校正的全分辨率数据文件 ace_xbt_corrected_1m/ace_xbt_YYYYMMDD_xxxx_uuuuuuuuuuuu_1m.XBT：逗号分隔值（CSV）格式，经经验校正的1米平均分辨率数据文件 辅助数据： ace_xbt_mld_tavg.csv：逗号分隔值（CSV）格式数据文件 ace_merged_ctd_xbt_mld_tsavg.csv：逗号分隔值（CSV）格式数据文件 图表文件： figure1.pdf：可移植文档格式（PDF）元数据文件 ace_xbt_figures/ace_xbt_YYYYMMDD_xxxx_1m.pdf：可移植文档格式（PDF）元数据文件 元数据： ace_xbt_deployment_summary.csv：逗号分隔值（CSV）格式元数据文件 data_file_header.txt：纯文本元数据文件 README.txt：纯文本元数据文件 数据集许可 本源自ACE任务的海水温度剖面数据集采用知识共享署名4.0国际许可协议（"Creative Commons Attribution 4.0 International License, CC BY 4.0"）发布，协议完整文本可在https://creativecommons.org/licenses/by/4.0/ 查询。