NOAA manages a fleet of Voluntary Observing Ships (VOS) that collect upper ocean temperature data using an Expendable Bathythermograph (XBT). The XBT's are launched by the ship's officers and crew along transects designated by large-scale oceanographic programs (e.g., the World Ocean Circulation Experiment and the Tropical-Ocean Global Atmosphere study). The NOAA fleet is one component of an international VOS effort.  The Atlantic Oceanographic and Meteorological Laboratory (AOML)  plays two roles in this international collection effort.  

First, as the Atlantic Ocean Science Center, AOML performs quality control of the delayed mode XBT data. Delayed mode data is periodically collected from the volunteer observing ships ship greeters or data submitted by scientisafter completion of a scientific research cruise. The quality control is internationally coordinated by the Global Temperature-Salinity Profile Project (GTSPP) which was initiated to develop a protocol for providing the highest quality temperature and salinity data to forecasters and researchers. AOML's delayed mode scientifically quality controlled data is summitted to NODC as part of the GTSPP where data can be found by clicking here.

Second, AOML's Global Ocean Observing System (GOOS) Center manages NOAA's component of the international VOS data collection effort.This management responsibilty is primarily focused on real-time data which is transmitted from ship to shore via satellite immediately after collection. AOML recruits new volunteer observing ships, maintains the hardware and software on each vessel, and tracks the data from collection until it is submitted to the national data centers. Finally, AOML/GOOS center employees develop the Shipboard Environmental (data) Acquisition Software (SEAS). SEAS is a multi-purpose software system which allows XBT profiles as well as weather observations, marine mammal sitings and many other environmental data to be sent via satellites, to collection centers around the world and in real time. These collection centers then circulate the data on the Global Telecommunications System to users worldwide.

SEAS Near Real Time XBT Data

The scientific quality control process is time consuming and labor intensive. The elapsed time between collection of the real-time profiles and scientific quality control is often as long as three years. With partial funding from the OAA Environmental Services Data and Information Mangamement group (ESDIM), AOML undertook an effort to automate the quality control of real time XBT profiles. The data included in this database are all XBT profiles transmitted by SEAS software and collected by the AOML GOOS Center. A conservative subset of the GTSPP quality control tests have been applied to the temperature profiles and the QC flags are available from the WWW interface as well. The subset of tests were chosen to eliminate only gross outliers typically due to transmission errors, instrument malfunction and incomplete or inaccurate metadata documentation. For example, profiles with temperature values outside the range of physically possible values (e.g. below freezing) or profiles with geographic coordinates on land, were not submitted to the GTS for global dissemination. Profiles which were unlikely, but not impossible were assessed visually by technicians. A subjective decision was made to determine if the profiles were dissemniated via the GTS. This conservative subset of tests does not flag all marginally acceptable data and it is left up to the individual scientists to determine if the profiles are realistic. Please contact us with any questions about the data.

Data Availability

Observation Dates: 2007/01/01 to 2008/05/19
Geographical Coordinates: latitude [55,-75] and longitude [-179,180]