Temperature profile data collected using XBTs from the PRESIDENT JEFFERSON from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 29 March 1977 to April 01 1977 (NODC Accession 8100161)

Temperature profile data were collected using bathythermograph (BT/XBT) casts from PRESIDENT JEFFERSON in the Pacific Ocean from March 29, 1977 to April 1, 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.

本数据集的温度-深度剖面数据采集于1977年3月29日至4月1日的太平洋海域，由“杰斐逊总统号”科考船通过温深仪（bathythermograph，BT/XBT）走航投放获取。相关数据由斯克里普斯海洋研究所提交，作为太平洋热结构监测计划（TRANSPAC）项目的组成部分。美国国家海洋数据中心（National Oceanographic Data Center，NODC）已将所有数据处理为符合其标准的通用温深仪输出格式（Universal Bathythermograph Output，UBT）。有关温深仪的完整说明可访问以下网址：http://www.nodc.noaa.gov/General/NODC-Archive/bt.html。

UBT格式存储了通过抛弃式温深仪（expendable bathythermograph，XBT）获取的温度-深度剖面数据。每条观测记录均包含航次信息、观测位置、观测日期与时间，数据记录由温度-深度值对构成。与机械式温深仪（Mechanical Bathythermograph，MBT）数据文件不同——后者以固定5米的间隔记录温度值，XBT数据文件的温度值对应的深度并非均匀分布。其深度测点仅保留足以精准刻画温度曲线的最少数量，即“拐点”（inflection points）。标准抛弃式温深仪可获取的剖面最大深度为450米或760米；若使用专用仪器，测量深度可达1830米。