A toga retrospective

The Tropical Ocean Global Atmosphere (TOGA) program was a 10-year international climate research effort carried out between 1985 and 1994 under the auspices of the World Climate Research Programme (WCRP). TOGA's goals were to determine the predictability of the coupled ocean-atmosphere system in the tropics on seasonal-to-interannual time scales, to understand the mechanisms responsible for that predictability, and to establish an observing system to support climate prediction. The US contribution to TOGA focused mainly on the El Niño/ Southern Oscillation (ENSO) phenomenon, which is the most prominent climate signal on seasonal-to-interannual time scales. One of TOGA's great strengths was that it forged the three fields of observation, theory, and modeling into a coherent program. TOGA also included climate impact studies from the very beginning by collaborating with scientists outside the field of physical climate research. This article highlights some key successes of TOGA and assesses its legacy from a perspective of progress over the past 15 years. It also celebrates the fiftieth anniversary of the Intergovernmental Oceanographic Commission (IOC), established within the United Nations Educational, Scientific and Cultural Organization to promote international cooperation in marine research, services, and observations. IOC, together with the World Meteorological Organization and the International Council of Science, co-sponsored not only TOGA, but also antecedent and follow-on climate research programs under WCRP. The continuity of these research programs over the time span of decades is one of the reasons for their long-term successes.