SFB754 CTD data and additional sensors used on the CTDO system

CTDO measurements were acquired on the major research cruises performed as part of the SFB 754 or other projects . Seabird 911plus systems equipped with dual temperature-conductivity-oxygen sensors were employed. All systems had a 24-bottle water sampling rosette with 10 l Niskin bottles. On some cruises only 22 bottles were mounted to accommodate a lowered Acoustic Doppler Current Profiler for deep ocean current observations. Water sampling, processing, and calibration followed GO-SHIP recommendations (Swift, 2010; McTaggart et al., 2010; Uchida et al., 2010) and included the recommended steps Data Conversion, Sensor Time-Alignment, Creation of Bottle Files, Outlier Removal, Pressure Sensor Filtering, Conductivity Cell Thermal Mass Correction, Ship Roll Correction and Deck Offset Correction by Loop Editing, as well as Derivation of Calculated Properties. After these steps, conductivity and oxygen readings were calibrated against values determined with salinometry and Winkler titration , respectively. Finally, the downcast data was averaged over 1 dbar wide intervals. An independent upcast calibration was used to obtain calibrated CTDO values coincident with the discrete water samples.

本数据集的CTDO测量数据采集自作为SFB 754项目或其他科研项目组成部分的主要科考航次。研究采用了配备双温盐氧传感器的Seabird 911plus型系统，所有系统均搭载24瓶式采水架，配备10升尼斯金（Niskin）采水瓶。部分航次仅安装22个采水瓶，以加装下放式声学多普勒流速剖面仪（Acoustic Doppler Current Profiler, ADCP）用于深海海流观测。采水、数据处理与校准工作均遵循全球海洋断面调查（GO-SHIP）的规范要求（Swift, 2010; McTaggart et al., 2010; Uchida et al., 2010），涵盖推荐的全部操作步骤：数据转换、传感器时间对齐、采水瓶数据文件生成、异常值剔除、压力传感器滤波、电导池热质量校正、船体横摇校正以及通过循环编辑完成的甲板偏移校正，同时还包括计算属性的推导。完成上述步骤后，分别利用盐度计测定值和温克勒（Winkler）滴定法测定值对电导率与溶解氧读数进行校准。最终，将下行剖面数据按1分巴（dbar）宽度的区间进行平均处理。通过独立的上行剖面校准流程，获得与离散采水样品匹配的校准后CTDO数据。