Temperature profile data collected using XBTs from the YAMASHIN MARU from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 23 July 1977 to 31 July 1977 (NODC Accession 8100198)

Temperature profile data were collected using bathythermograph (BT/XBT) casts from YAMASHIN MARU in the Pacific Ocean from July 23, 1977 to July 31, 1977. Data were submitted by Scripps Institution of Oceanography as part of the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project. Data were processed by NODC to the NODC standard Universal Bathythermograph Output (UBT) format. Full BT descriptions are available at http://www.nodc.noaa.gov/General/NODC-Archive/bt.html.

The UBT format contains temperature-depth profile data obtained using expendable bathythermograph (XBT) instruments. Cruise information, position, date and time were reported for each observation. The data record was comprised of pairs of temperature-depth values. Unlike the MBT Data File, in which temperature values were recorded at uniform 5 m intervals, the XBT data files contained temperature values at non-uniform depths. These depths were recorded at the minimum number of points (''inflection points'') required to accurately define the temperature curve. Standard XBTs can obtain profiles to depths of either 450 or 760 m. With special instruments, measurements can be obtained to 1830 m.

本数据集收录了1977年7月23日至7月31日期间，“山真丸”号（YAMASHIN MARU）在太平洋海域通过深海测温仪（bathythermograph, BT/XBT）走航投放获取的温度剖面数据。该数据由斯克里普斯海洋研究所（Scripps Institution of Oceanography）作为太平洋热结构监测计划（TRANSPAC项目）的一部分提交存档。美国国家海洋数据中心（National Oceanographic Data Center, NODC）已将原始数据处理为符合其标准的通用深海测温仪输出格式（Universal Bathythermograph Output, UBT）。有关BT仪器的完整说明文档，可通过链接http://www.nodc.noaa.gov/General/NODC-Archive/bt.html 查询获取。

UBT格式存储了通过投弃式深海测温仪（expendable bathythermograph, XBT）采集得到的温度-深度剖面数据。每条观测记录均配套记录了航次信息、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。与采用均匀5米间隔记录温度的MBT数据文件不同，XBT数据文件的温度测点采用非均匀深度分布，仅在精准刻画温度变化曲线所需的最少测点（即“拐点”）处记录温度值。标准XBT仪器可获取最大深度为450米或760米的温度剖面；若配备特殊定制仪器，测量深度可达1830米。