Current direction, bathythermograph (xbt), CTD, and other data from moored current meter casts and other instruments in the Coastal Waters of California as part of the North California Coastal Circulation Study (NCCCS) project, 1987-03-09 to 1989-11-01 (NODC Accession 9000209)

Current direction, bathythermograph (xbt), CTD, and other data were collected using moored current meter casts and other instruments in the Coastal Waters of California from March 9, 1987 to November 1, 1989. Data were submitted by Edgerton, Germeshausen and Grier, INC. as part of the North California Coastal Circulation Study (NCCCS) project. Data has been been processed by NODC to the NODC standard F015- Current Meter Data, F022- CTD High Resolution, and C116- Bathythermograph XBT formats. Full format descriptions are available from NODC homepage at http://www.noaa.nodc.gov.

The F015 format is used for time series measurements of ocean currents. These data are obtained from current meter moorings and represent Eulerian method of current measurement, i.e., the meters are deployed at a fixed point and measure flow past a sensor. Position, bottom depth, sensor depth, and meter characteristics are reported for each station. The data record comprises values of east-west (u) and north-south (v) current vector components at specified date and time. Current direction is defined as the direction toward which the water is flowing with positive directions east and north and negative directions west and south. Data values may be subject to averaging or filtering and are typically reported at 10-15 minute time intervals. Water temperature, pressure, and conductivity or salinity may also be reported. A text record is available for optional comments.

The F022 format contains high-resolution data collected using CTD (conductivity-temperature-depth) and STD (salinity-temperature-depth) instruments. As they are lowered and raised in the oceans, these electronic devices provide nearly continuous profiles of temperature, salinity, and other parameters. Data values may be subject to averaging or filtering or obtained by interpolation and may be reported at depth intervals as fine as 1m. Cruise and instrument information, position, date, time and sampling interval are reported for each station. Environmental data at the time of the cast (meteorological and sea surface conditions) may also be reported. The data record comprises values of temperature, salinity or conductivity, density (computed sigma-t), and possibly dissolved oxygen or transmissivity at specified depth or pressure levels. Data may be reported at either equally or unequally spaced depth or pressure intervals. A text record is available for comments.

The C116 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. Prior to July 1994, XBT data were routinely processed to one of these standard types. XBT data are now processed and loaded directly in to the NODC Ocean Profile Data Base (OPDB). Historic data from these two data types were loaded into the OPDB.

海流数据、测温深仪（Bathythermograph, XBT）、CTD（电导率-温度-深度仪，Conductivity-Temperature-Depth）及其他类型数据，于1987年3月9日至1989年11月1日期间，通过锚定海流计投放及其他仪器设备，在加利福尼亚近岸海域采集完成。数据由Edgerton, Germeshausen and Grier, INC. 提交，作为北加利福尼亚近岸环流研究（North California Coastal Circulation Study, NCCCS）项目的组成部分。所有数据已由美国国家海洋数据中心（National Oceanographic Data Center, NODC）按照NODC标准格式进行处理，涵盖F015-海流计数据、F022-高分辨率CTD数据以及C116-XBT测温深仪数据格式。完整的格式说明可从NODC官网http://www.noaa.nodc.gov 获取。

F015格式用于海流的时间序列测量。此类数据取自锚定海流计，采用欧拉法（Eulerian method）进行海流测量，即仪器部署于固定点位，监测流经传感器的水流。每个测站均记录其位置、海底水深、传感器布设深度以及海流计的相关参数。数据记录包含指定日期与时刻下的东西向（u）与南北向（v）海流矢量分量数值。海流方向定义为水流流向，以东向与北向为正方向，西向与南向为负方向。数据值可经过平均或滤波处理，通常以10至15分钟的时间间隔进行记录。此外还可记录海水温度、压力以及电导率或盐度数据。数据集附带文本记录字段，用于填写可选备注信息。

F022格式包含采用CTD与STD（盐度-温度-深度仪，Salinity-Temperature-Depth）采集的高分辨率数据。此类电子设备在海洋中升降作业时，可获取温度、盐度及其他参数的近乎连续的剖面数据。数据值可经过平均、滤波处理或通过插值得到，最小可按1米的深度间隔进行记录。每个测站均记录航次与仪器信息、位置、日期、时间以及采样间隔。此外还可记录投放时刻的环境数据（气象与海面状况）。数据记录包含指定深度或压力层位下的温度、盐度或电导率、密度（计算得到的σ-t），以及可能存在的溶解氧或透射率数值。数据可按等间距或不等间距的深度或压力间隔进行记录。数据集附带文本记录字段用于填写备注。

C116格式包含采用抛弃式测温深仪（Expendable Bathythermograph, XBT）获取的温度-深度剖面数据。每个观测记录均包含航次信息、位置、日期与时间。数据记录由温度-深度值对组成。与MBT数据文件（其温度值按统一的5米间隔记录）不同，XBT数据文件中的温度值对应非均匀的深度间隔，此类深度仅记录准确绘制温度曲线所需的最少点数（即“拐点”）。标准XBT可获取450米或760米水深范围内的剖面数据；通过专用仪器，测量深度可达1830米。1994年7月之前，XBT数据通常按上述标准类型之一进行处理。目前XBT数据可直接经处理后载入NODC海洋剖面数据库（Ocean Profile Data Base, OPDB），此前这两类数据的历史记录也已一并载入该数据库。