Temperature profiles from expendable bathythermograph (XBT) casts from the USCGC MELLON in the Bering Sea and North Pacific Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 20 October 1976 to 31 October 1976 (NODC Accession 7601868)

XBT data were collected from the USCGC MELLON in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the US Coast Guard (USCG) from 20 October 1976 to 31 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XBT（投弃式海水温度剖面仪，expendable bathythermograph）数据采集自美国海岸警卫队“梅隆”号（USCGC MELLON），用于支持综合全球海洋服务系统（Integrated Global Ocean Services System，简称IGOSS）项目。数据由美国海岸警卫队（US Coast Guard，简称USCG）于1976年10月20日至1976年10月31日期间采集，后由美国国家海洋数据中心（National Oceanographic Data Center，简称NODC）按照NODC标准通用深度温度记录仪输出（Universal Bathythermograph Output，简称UBT）格式完成标准化处理。完整格式说明可通过NODC官方网站www.nodc.noaa.gov/General/NODC-Archive/bt.html查询获取。

UBT文件格式用于存储通过XBT仪器获取的温度-深度剖面数据。标准型XBT可获取深度约450米或760米范围内的剖面数据；配置专用仪器时，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-深度值对组成。与以5米均匀间隔记录温度值的机械式海水温深仪（MBT）数据文件不同，XBT数据文件中的温度值对应非均匀深度测点，这些测点为以可接受精度完整记录温度曲线所需的最少点数（即“拐点”）。但在数据输出环节，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。