Vertical structure reveals eddy lifetime in the Greenland Sea

Recently observed coherent vortices in the central Greenland Sea are regarded as possible contributors to local deep water formation. Within them, winter convection distributes surface waters to considerably greater depths than elsewhere ( up to 2700 m vs 1500 m). The lifetime of coherent vortices is an important open question, which determines the volume flux into deep waters. Here, we present previously lacking direct evidence for a lifetime of more than two years from a detailed analysis of the vertical structure within a vortex core on the base of hydrographic observations in 2005.