Temperature profiles from expendable bathythermograph (XBT) casts from NOAA Ship RAINIER in the North Pacific Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 1983-08-21 to 1983-08-25 (NODC Accession 8300135)

XBT data were collected from NOAA Ship RAINIER in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the National Ocean Service (NOS) from 21 August 1983 to 25 August 1983. Data were processed by NODC to the NODC standard Universal Bathythermograph Output (UBT) format. Full format description is available from NODC at www.nodc.noaa.gov/General/NODC-Archive/bt.html.

The UBT file format is used for temperature-depth profile data obtained using expendable bathythermograph (XBT) instruments. Standard XBTs can obtain profiles at depths of about 450 or 760 m. With special instruments, measurements can be obtained to 1830 m. Cruise information, position, date, and time are reported for each observation. The data record comprises pairs of temperature-depth values. Unlike the MBT data file, in which temperature values are recorded at uniform 5m intervals, the XBT Data File contains temperature values at non-uniform depths. These depths are at a minimum number of points ("inflection points") required to record the temperature curve to an acceptable degree of accuracy. On output, however, the user may request temperature values either at inflection points or interpolated to uniform depth increments.

本数据集包含的XBT（投弃式温深仪，expendable bathythermograph）数据采集自美国国家海洋和大气管理局（NOAA）“雷尼尔”号科考船，用于支撑综合全球海洋服务系统（Integrated Global Ocean Services System，缩写IGOSS）项目。数据由美国国家海洋服务局（National Ocean Service，缩写NOS）于1983年8月21日至8月25日采集完成，后由美国国家海洋数据中心（National Oceanographic Data Center，缩写NODC）处理为符合NODC标准的通用温深仪输出（Universal Bathythermograph Output，缩写UBT）格式。完整格式说明可通过NODC官网（www.nodc.noaa.gov/General/NODC-Archive/bt.html）查阅获取。

UBT文件格式用于存储通过投弃式温深仪获取的温度-深度剖面数据。标准XBT可获取深度约450米或760米的剖面数据；搭配专用仪器时，测量深度可达1830米。每条观测记录均包含航次信息、观测位置、日期与时间，数据记录由多组温度-深度数值对组成。与MBT（机械温深仪，Mechanical Bathythermograph）数据文件不同，后者以均匀5米的间隔记录温度值，而XBT数据文件中的温度值对应非均匀分布的深度。这些深度点为以可接受精度记录温度曲线所需的最少点数，即“拐点”。不过在数据输出环节，用户可选择获取拐点处的温度值，或通过插值得到均匀深度间隔下的温度数值。