Temperature profiles from expendable bathythermograph (XBT) casts from the KNORR in the North Atlantic Ocean in support of the Integrated Global Ocean Services System (IGOSS) from 07 March 1975 to 12 April 1975 (NODC Accession 7500580)

XBT data were collected from the KNORR in support of the Integrated Global Ocean Services System (IGOSS). Data were collected by Woods Hole Oceanographic Institution (WHOI) from 07 March 1975 to 12 April 1975. 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.抛弃式温深仪（Expendable Bathythermograph，XBT）数据由“克诺尔号”（KNORR）科考船采集，用于支撑全球海洋综合服务系统（Integrated Global Ocean Services System，IGOSS）。该数据由伍兹霍尔海洋研究所（Woods Hole Oceanographic Institution，WHOI）于1975年3月7日至1975年4月12日期间采集完成。美国国家海洋数据中心（National Oceanographic Data Center，NODC）将所有数据处理为符合NODC标准的通用温深仪输出（Universal Bathythermograph Output，UBT）格式。完整的格式说明可从NODC官网的https://www.nodc.noaa.gov/General/NODC-Archive/bt.html获取。 UBT文件格式用于存储通过XBT采集的温度-深度剖面数据。标准型XBT可获取最大深度约450米或760米的温度剖面；若配备专用仪器，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，数据记录由温度-深度值对组成。与船载温深仪（Mechanical Bathythermograph，MBT）数据文件不同——后者以每5米的固定间隔记录温度值，XBT数据文件的温度值对应非均匀的深度采样点。这些深度为记录温度曲线至可接受精度所需的最少点数（即“拐点”）。在数据输出环节，用户可选择获取拐点处的原始温度值，或是将其插值为均匀深度间隔的温度数据。