Frequently asked questions bout ocean observations

For more information on Argo data management activities of the Physical Oceanography Division of NOAA’s Atlantic Oceanographic and Meteorological Laboratory go to:

http://www.aoml.noaa.gov/phod/sardac/index.php

2. 
   How has the distribution of XBT and Argo floats evolved with time?
   

3. 
   How has the distribution of surface drifters evolved with time?
   

The surface drifter program started as part of the Tropical Ocean Global Atmosphere project, which focused on El Nino variability in the Pacific Ocean. Thus, early deployments (starting in 1979) were in the eastern equatorial Pacific region. As late as 1989, nearly all deployments were still conducted across the tropical Pacific basin, with very few in the tropical Indian Ocean (starting in 1985). The situation changed quickly over the next ten years, with the creation of the Global Drifter Program and emphasis on a truly global array of drifters at a nominal resolution of 5x5 degrees. Dense and regular deployments began in earnest in the North Atlantic in 1989, and throughout the Pacific and Southern oceans in the early 1990s. Deployments commenced in the South Atlantic in 1993, and sustained annual deployments in the Indian Ocean began in 1994. Finally, regular deployments in the Tropical Atlantic began in 1997. By 2000, there were over 600 drifters in all major ocean basins. In September 2005, the program reached its goal of 1250 drifters worldwide, and has subsequently maintained an array of approximately that size.