Temperature profiles from expendable bathythermograph (XBT) casts from the USCGC BOUTWELL in the North Pacific Ocean in support of the Integrated Global Ocean Services System (IGOSS) from 05 June 1975 to 29 June 1975 (NODC Accession 7500705)

XBT data were collected from the USCGC BOUTWELL in support of the Integrated Global Ocean Services System (IGOSS). Data were collected by the US Coast Guard from 05 June 1975 to 29 June 1975. 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.

本数据集的抛弃式温深计（Expendable Bathythermograph，XBT）数据采集自美国海岸警卫队巴特维尔号（USCGC BOUTWELL），用于支撑全球海洋综合服务系统（Integrated Global Ocean Services System，IGOSS）的运行。数据采集工作由美国海岸警卫队于1975年6月5日至1975年6月29日期间完成。数据由美国国家海洋数据中心（National Oceanographic Data Center，NODC）按照其通用温深计输出（Universal Bathythermograph Output，UBT）标准格式进行处理。完整的格式说明可从NODC官网获取，网址为：www.nodc.noaa.gov/General/NODC-Archive/bt.html。

UBT文件格式用于存储通过抛弃式温深计（XBT）获取的温度-深度剖面数据。标准型XBT可获取深度约450米或760米的剖面数据；若使用专用仪器，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、观测日期与时间。数据记录由多组温度-深度值对构成。与机械温深计（Mechanical Bathythermograph，MBT）数据文件不同——后者以每5米的固定间隔记录温度值，本XBT数据文件中的温度值对应非均匀的深度。这些深度点为以可接受的精度记录温度曲线所需的最少点数（即“拐点”）。但在数据输出时，用户可选择获取拐点处的原始温度值，或通过插值得到均匀深度间隔下的温度值。