A major goal for oceanography in the next decade is an understanding of ocean dynamics at basin and global spatial scales and at time scales from the interannual through the decadal. This understanding is not only of intrinsic interest and importance for the oceans themselves but is an essential component of the larger problems concerning the cycles of heat, water, and chemical constituents through the land, air, and sea. To the extent that the oceans act as the “flywheel” for the total system at these longer time scales, our level of understanding of this component is likely to be critical.