Temperature profiles from expendable bathythermograph (XBT) casts from the USCGC GLACIER in the North Pacific Ocean in support of the Integrated Global Ocean Services System (IGOSS) from 27 July 1976 to 27 October 1976 (NODC Accession 7601803)

XBT data were collected from the USCGC GLACIER in support of the Integrated Global Ocean Services System (IGOSS). Data were collected by the US Coast Guard from 27 July 1976 to 27 October 1976. 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.

本数据集的投弃式温深计（expendable bathythermograph, XBT）数据采集自美国海岸警卫队冰川号（USCGC GLACIER）科考船，服务于综合全球海洋服务系统（Integrated Global Ocean Services System, IGOSS）。数据由美国海岸警卫队于1976年7月27日至1976年10月27日期间采集，后由美国国家海洋数据中心（National Oceanographic Data Center, NODC）按照其制定的标准通用温深计输出（Universal Bathythermograph Output, UBT）格式完成标准化处理。完整格式说明可从美国国家海洋数据中心官网www.nodc.noaa.gov/General/NODC-Archive/bt.html获取。
UBT文件格式用于存储通过投弃式温深计（XBT）获取的温度-深度剖面数据。标准型XBT可获取约450米或760米水深范围内的温度剖面；若搭载特制仪器，测量水深可达1830米。每条观测记录均附带航次信息、观测位置、观测日期与时间。数据记录由多组温度-深度数值对构成。与以固定5米间隔记录温度值的机械式温深计（Mechanical Bathythermograph, MBT）数据文件不同，XBT数据文件中的温度值并非对应均匀水深间隔，而是仅记录能够以可接受精度还原温度曲线所需的最少拐点（inflection points）处的数据。不过在数据输出环节，用户可选择获取拐点处的原始温度数据，或通过插值得到均匀水深增量下的温度值。