Open-ocean convection: Observations, theory, and models

We review what is known about the convective process in the open ocean, in which the properties of large volumes of water are changed by intermittent, deep-reaching convection, triggered by winter storms. Observational, labor atory, and modeling studies reveal a fascinating and complex interplay of c onvective and geostrophic scales, the large-scale circulation of the ocean, and the prevailing meteorology. Two aspects make ocean convection interest ing from a theoretical point of view. First, the timescales of the convecti ve process in the ocean are sufficiently long that it may be modified by th e Earth's rotation; second, the convective process is localized in space so that vertical buoyancy transfer by upright convection can give way to slan twise transfer by baroclinic instability. Moreover, the convective and geos trophic scales are not very disparate from one another. Detailed observatio ns of the process in the Labrador, Greenland, and Mediterranean Seas are de scribed, which were made possible by new observing technology. When interpr eted in terms of underlying dynamics and theory and the context provided by laboratory and numerical experiments of rotating convection, great progres s in our description and understanding of the processes at work is being ma de.