Temperature profiles from XBT and AXBT casts from the CHASE and AIRCRAFT from Ocean Weather Station B (OWS-B) in the North Atlantic Ocean from 11 December 1973 to 01 January 1975 (NODC Accession 7400108)

Bathythermograph data were collected from the CHASE and AIRCRAFT within a 1-mile radius of Ocean Weather Station B (5630N 05100W) and in transit. Data were collected by the United States Coast Guard and US Navy; Ships of Opportunity from 11 December 1973 to 01 January 1975. The platform was equipped and staffed to observe weather and sea conditions. 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) instrument. 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.

本数据集的温深仪（Bathythermograph）数据采集自海洋气象站B（56°30′N，051°00′W）周边1英里范围内的CHASE与AIRCRAFT平台及航行途中。数据由美国海岸警卫队、美国海军及机会性商船收集，采集时段为1973年12月11日至1975年1月1日。该平台配备观测设备与值守人员，用于开展气象与海洋状况观测。数据已由美国国家海洋数据中心（NODC，National Oceanographic Data Center）处理为符合NODC标准的通用温深仪输出（Universal Bathythermograph Output, UBT）格式。完整格式说明可通过NODC官网www.nodc.noaa.gov/General/NODC-Archive/bt.html获取。

UBT文件格式用于存储通过投弃式温深仪（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米的温度剖面，若搭载专用测量仪器，最大测量深度可达1830米。每条观测记录均包含航行信息、观测位置、日期与时间。数据记录由多组温度-深度值对构成。与以均匀5米间隔记录温度值的机械式温深仪（Mechanical Bathythermograph, MBT）数据文件不同，XBT数据文件的温度值对应非均匀深度间隔，这些深度点为以可接受精度完整记录温度曲线所需的最少拐点数量。但在数据输出阶段，用户可选择按原始拐点位置输出温度值，或通过插值得到均匀深度增量下的温度数据。