Bathythermograph (XBT), high-resolution CTD/STD, ocean station data from KAKADIAMAA, NOAA Ship Oregon II, and others in the Arabian Sea, Bay of Bengal, and others from 1979-01-17 to 1983-02-11 (NCEI Accession 8300036)

This dataset includes bathythermograph (XBT), high-resolution CTD/STD, ocean station data from KAKADIAMAA, NOAA Ship Oregon II, R/V WECOMA, SAKUMO, USS Decatur, USS MISSISSIPPI, USS STARK, and USS Scott in the Arabian Sea, Bay of Bengal, Gulf of Guinea, Gulf of Mexico, Indian Ocean, Laccadive Sea, Mediterranean Sea, North Atlantic Ocean, North Pacific Ocean, and South China Sea from 1979-01-17 to 1983-02-11.

Data has been processed by NODC to the NODC standard Bathythermograph (XBT) (C116), High-Resolution CTD/STD (F022), and Ocean Station (C100) formats.

The Oceanographic Station Data (C100) format contains physical-chemical oceanographic data recorded at discrete depth levels. Most of the observations were made using multi-bottle Nansen casts or other types of water samplers. A small amount (about 5 percent) were obtained using electronic CTD (conductivity-temperature-depth) or STD (salinity-temperature-depth) recorders. The CTD/STD data were reported to NODC at depth levels equivalent to Nansen cast data, however, and have been processed and stored the same as the Nansen data. Cruise information (e.g., ship, country, institution), position, date, and time, and reported for each station. The principal measured parameters and temperature and salinity, but dissolved oxygen, phosphate, total phosphorus, silicate, nitrate, nitrite, and pH may be reported. Meteorological conditions at the time of the cast (e.g., air temperature and pressure, wind, waves) may also be reported, as well as auxiliary data such as water color (Forel-Ule scale), water transparency (Secchi disk depth), and depth to bottom. Values of density (sigma-t) sound velocity, and dynamic depth anomaly are computed from measured parameters. Each station contains the measurements taken at the observed depth levels, but also includes data values interpolated to a set of standard depth levels.

The C116/C118 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.

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.

Tags: oceanography, w8112a, w8112b
Organization: National Oceanic and Atmospheric Administration, Department of Commerce