Temperature profile data collected using XBT and BT casts in a World-wide distribution from NOAA Ship RESEARCHER and other platforms from 1970-09-30 to 1979-08-05 (NODC Accession 8300089)

Temperature profile data were collected using XBT and BT casts from NOAA Ship RESEARCHER and other platforms in a World-wide distribution from 30 September 1970 to 05 August 1979. Data were collected by the US NAVY; Ships of Opportunity. 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本数据集的温度剖面数据采集于1970年9月30日至1979年8月5日期间，由美国海军"机遇舰船（Ships of Opportunity）"项目借助NOAA"RESEARCHER"号科考船及其他观测平台，通过投放一次性海水温度剖面仪（expendable bathythermograph, XBT）和BT剖面仪获取，观测范围覆盖全球海域。数据经美国国家海洋数据中心（National Oceanographic Data Center, NODC）处理，统一采用NODC标准通用海水温度剖面仪输出（Universal Bathythermograph Output, UBT）格式存储。完整格式说明可通过NODC官网www.nodc.noaa.gov/General/NODC-Archive/bt.html 获取。 UBT文件格式专用于存储通过一次性海水温度剖面仪（XBT）获取的温度-深度剖面数据。标准型XBT可获取最大深度约450米或760米的剖面数据，搭载特殊型号仪器时，测量深度可达1830米。每条观测记录均附带航次信息、观测位置、日期及时间。数据记录由多组温度-深度数值对构成。与采用5米等间隔记录温度值的机械海水温度剖面仪（Mechanical Bathythermograph, MBT）数据文件不同，XBT数据文件的温度值采样深度为非均匀分布：仅在能够以可接受精度还原温度曲线所需的最少拐点处记录数据。不过在数据输出时，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数据。