Temperature profile data from XBT and BT casts in the Gulf of Mexico through NOAA Ship RESEARCHER from 29 August 1978 to 30 August 1978 (NODC Accession 8000561)

Temperature profile data were collected using XBT and BT casts from the NOAA Ship RESEARCHER in the Gulf of Mexico from 29 August 1978 to 30 August 1978. Data were collected by the Atlantic Oceanographic and Meteorological Laboratory (AOML) in Miami, Florida. 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.

本数据集为温度剖面数据，采集于1978年8月29日至1978年8月30日期间，由美国国家海洋和大气管理局（NOAA）的“RESEARCHER”号科考船在墨西哥湾开展的抛弃式温深计（XBT，Expendable Bathythermograph）与温深计（BT，Bathythermograph）投放作业获取。数据由位于佛罗里达州迈阿密的大西洋海洋与气象实验室（AOML，Atlantic Oceanographic and Meteorological Laboratory）采集完成，后由国家海洋数据中心（NODC，National Oceanographic Data Center）处理为符合NODC标准的通用温深计输出（UBT，Universal Bathythermograph Output）格式。完整的格式说明可从NODC官网获取，网址为www.nodc.noaa.gov/General/NODC-Archive/bt.html。

UBT文件格式用于存储通过抛弃式温深计（XBT）获取的温度-深度剖面数据。标准型XBT可获取约450米或760米水深范围内的剖面数据；搭载专用仪器时，测量水深可达1830米。每条观测记录均包含航次信息、站位坐标、观测日期与时间。数据记录由温度-深度值对组成。与MBT数据文件（其温度值按均匀5米间隔记录）不同，XBT数据文件中的温度值对应非均匀水深。这些水深点为以可接受精度记录温度曲线所需的最少点数，即“拐点”。不过在输出时，用户可选择获取拐点处的温度值，或通过插值得到均匀深度间隔下的温度值。