Present investigations of ocean-atmosphere interactions involve two concepts. The first is derived from experiments which suggest that regions in the ocean may significantly affect large-scale atmospheric processes over the continents, with a time-lag of 4-8 months. The second concept is a hypothesis that may help explain climate variability and large-scale weather anomalies. It assumes that water masses with abnormal temperatures may persist for long periods, are able to reach deep waters and migrate for long distances, and under certain conditions may reappear at the surface and induce large-scale anomalies of atmospheric circulation several months, or more probably, years later. These interactions of the ocean and the atmosphere determine the world's weather and are responsible for droughts, floods, storms, and other extreme weather conditions which take an annual toll in lives, crops, and property damage.