Temperature profiles from expendable bathythermograph (MBT) casts from the USCGC JARVIS in the North Pacific Ocean in support of the Integrated Global Ocean Services System (IGOSS) from 17 February 1976 to 12 March 1976 (NODC Accession 7600748)

XBT data were collected from the USCGC JARVIS in support of the Integrated Global Ocean Services System (IGOSS). Data were collected by the US Coast Guard from 17 February 1976 to 12 March 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仪（Expendable Bathythermograph, XBT）数据由美国海岸警卫队贾维斯号（USCGC JARVIS）采集，服务于全球海洋综合服务系统（Integrated Global Ocean Services System, IGOSS）。该数据的采集时段为1976年2月17日至1976年3月12日，由美国海岸警卫队实施，后经美国国家海洋数据中心（National Oceanographic Data Center, NODC）处理为NODC标准通用温深仪输出（Universal Bathythermograph Output, UBT）格式。完整格式说明可通过NODC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仪（XBT）获取的温度-深度剖面数据。标准型XBT可获取约450米或760米水深范围内的剖面数据，配备专用仪器时则可实现最深1830米的测量。每条观测记录均包含航次信息、观测位置、日期与时间，数据记录由温度-深度值对构成。与机械式温深仪（Mechanical Bathythermograph, MBT）数据文件采用均匀5米间隔记录温度值不同，XBT数据文件的温度值对应非均匀水深。这些非均匀水深点为满足温度曲线可接受的记录精度所需的最少测点（即"拐点"）。不过在数据输出时，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数据。