Temperature profiles from expendable bathythermograph (XBT) casts from the USCGC EVERGREEN in the North Atlantic Ocean in support of the Integrated Global Ocean Services System (IGOSS) from 04 April 1972 to 22 April 1972 (NODC Accession 7200693)

XBT data were collected from the USCGC EVERGREEN in support of the Integrated Global Ocean Services System (IGOSS). Data were collected by the US Coast Guard from 04 April 1972 to 22 April 1972. 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（抛弃式深海测温仪，expendable bathythermograph）数据由美国海岸警卫队常青号（USCGC EVERGREEN）采集，用于支撑综合全球海洋服务系统（Integrated Global Ocean Services System，IGOSS）。数据采集时段为1972年4月4日至1972年4月22日，由美国海岸警卫队完成现场采集。后续由国家海洋数据中心（National Oceanographic Data Center，NODC）按照其制定的通用深海测温仪输出（Universal Bathythermograph Output，UBT）标准格式对数据进行统一处理。完整的格式说明文档可通过NODC官方网站获取：www.nodc.noaa.gov/General/NODC-Archive/bt.html。 UBT文件格式专用于存储通过抛弃式深海测温仪（expendable bathythermograph，XBT）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米的剖面数据；若搭载专用型号设备，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、观测日期与时间。数据记录由多组温度-深度数值对构成。与温度采样间隔为固定5米的MBT数据文件不同，XBT数据文件中的温度值对应的采样深度并非均匀分布，而是选取了最少数量的“拐点”以可接受的精度完整记录温度变化曲线。但在数据输出阶段，用户可自行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。