Temperature profiles from XBT casts from the GRESHAM from Ocean Weather Station H (OWS-H) in the North Atlantic Ocean from 06 February 1973 to 22 March 1973 (NODC Accession 7300429)

Bathythermograph data were collected from the GRESHAM within a 1-mile radius of Ocean Weather Station H (3800N 07100W) and in transit. Data were collected by the United States Coast Guard from 06 February 1973 to 22 March 1973. 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.

本数据集包含GRESHAM号船只在海洋气象站H（38°00′N，71°00′W）周边1英里范围内及航行途中收集的海洋测温仪（Bathythermograph）数据。数据采集工作由美国海岸警卫队于1973年2月6日至1973年3月22日期间开展。该观测平台配备专业设备并配有操作人员，用于开展气象与海洋环境状况观测。所有数据已由国家海洋数据中心（National Oceanographic Data Center，简称NODC）处理为NODC标准通用海洋测温仪输出（Universal Bathythermograph Output，简称UBT）格式。完整格式说明可从NODC官网www.nodc.noaa.gov/General/NODC-Archive/bt.html获取。

UBT文件格式用于记录使用投弃式海洋测温仪（expendable bathythermograph，简称XBT）获取的温度-深度剖面数据。标准XBT可获取约450米或760米深度的温度剖面；使用专用仪器时，测量深度可达1830米。每份观测记录均包含航次信息、观测位置、日期与时间。数据记录由多组温度-深度数值对构成。与机械海洋测温仪（Mechanical Bathythermograph，简称MBT）数据文件不同——MBT数据文件以5米等间隔记录温度数值——XBT数据文件中的温度数值对应非均匀分布的深度。这些深度点为以可接受精度记录温度曲线所需的最少点数（即“拐点”）。但在输出时，用户可选择获取拐点处的原始温度数值，或通过插值得到均匀深度间隔下的温度数值。