Temperature profiles from expendable bathythermograph (XBT) casts from the NOAA Ship RAINIER in the Gulf of Alaska in support of the Integrated Global Ocean Services System (IGOSS) project from 03 June 1979 to 04 June 1979 (NODC Accession 8000288)

XBT data were collected from the NOAA Ship RAINIER in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the National Ocean Service (NOS) from 03 June 1979 to 04 June 1979. 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数据由美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration，NOAA）“雷尼尔号”科考船采集，以支撑综合全球海洋服务系统（Integrated Global Ocean Services System，IGOSS）项目。数据由美国国家海洋服务局（National Ocean Service，NOS）于1979年6月3日至1979年6月4日采集，后经美国国家海洋数据中心（National Oceanographic Data Center，NODC）处理为符合NODC标准的一次性深海温深仪输出（Universal Bathythermograph Output，UBT）格式。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一次性深海温深仪（expendable bathythermograph，XBT）获取的温深剖面数据。标准型XBT可获取深度约450米或760米的温深剖面；若搭载专用测量设备，最大测量深度可达1830米。每份观测数据均包含航次信息、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。与温度值按均匀5米间隔记录的机械温深仪（MBT）数据文件不同，XBT数据文件的温度值对应非均匀深度，这些深度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”）。不过在数据输出环节，用户可选择直接获取拐点处的温度值，或通过插值得到均匀深度增量下的温度值。