NDBC's Drifting Buoy Program
NDBC is a national leader in the design, development, acquisition, and operational use of drifting buoys. Drifters are expendable systems launched from ships or aircraft into specific ocean areas. As they drift in response to ocean currents and winds, they make measurements of the atmospheric pressure, air and sea temperature, wind speed, and wind direction.
Data from drifting buoys are relayed to ground stations via NOAA polar orbiting environmental satellites (POES). Because these satellites are not geostationary, data are available only when the orbiting satellite is within sight of the buoy. At that time, the buoy data are sent to the spacecraft. From the satellite, data are either relayed immediately to any ground receiving station in view, or stored on board until the satellite moves over special ground stations at Gilmore Creek, Alaska; Lannion, France; or Wallops Island, Virginia. A buoy's position is determined each time a message is processed, thus allowing drift determination.
The special ground stations receive both the real time and stored measurements from the satellite, then relay them to facilities operated by Service Argos, Inc., in Landover, Maryland. At Service Argos, observations are processed and formatted, then forwarded to the NWSTG where further processing, such as quality checks, are performed prior to release to users in a manner similar to that for moored buoys and C-MAN sites.
Drifting buoys have an excellent performance record in global research, such as in the Global Atmospheric Research Program (GARP). Drifters were first deployed in large numbers for the First GARP Global Experiment (FGGE) in the late 1970's. In the mid-1980's, drifters began to be deployed in support of the Tropical Ocean and Global Atmosphere (TOGA) Research Program. Over 330 drifting buoys have been deployed for TOGA into some of the most severe environments on earth, and most have operated for 12 to 18 months. Drifting buoys have been used in a variety of other scientific programs, including projects sponsored by the U.S. Departments of Commerce, Interior, and Defense, as well as international organizations. One notable experiment included the successful deployment of four drifters in advance of Hurricane Josephine in 1984 and the associated data recovery and evaluation. The latest drifter deployment is in the North Pacific.
Development of additional capability in drifting buoys is ongoing at NDBC. Current activities include testing of less costly barometers, improved wind measurements, and wave measurements.