Expendable Bathythermograph (XBT) Program

The GOOS Center operates a global XBT Program that utilizes approximately 70 Voluntary Observing Ships (VOS) to monitor, on a monthly basis, 26 transects in all three ocean basins (see GOOS network plot). The GOOS Center utilizes Shipboard Environmental data Acquisition Systems (SEAS) hardware/software to collect, quality control and transmit in real-time subsurface oceanographic observations (about 15,000 per year) and sea surface meteorological observations (about 110,000 per year). The XBT is an expendable temperature probe that is manually launched from the bridge wings of commercial vessels approximately 4 times per day, along certain scientifically selected shipping lanes. The data transmitted via the wire link from the XBT probe is stored on the SEAS computer where it is processed and formatted for satellite message transmission. The transmitted data is routed to the GOOS Center where it is further quality controlled and then inserted on to the Global Telecommunication System (GTS) for global distribution. The National Center for Environmental Predication (NCEP) uses this data for weather and climate forecasting as well as for seasonal, interannual and decadel climate research. The XBT program is a participating member of the Intergovernmental Oceanographic Commission (IOC) - World Meteorological Organization (WMO), Ship of Opportunity Program Implementation Panel (SOOPIP) and as such represents NOAA in this international forum.