In contrast to the gyre-scale, heavily-smoothed view of EDW evolution available to us with previous observations, we plan to describe in detail the process of EDW formation and evolution using a combination of moorings, floats, and shipboard observations. Measurements will be focused on a region of active EDW formation just south of the Gulf Stream and will resolve time and space scales compatible with those of the winter observations.
The specific goals of this effort are to:
Three linked approaches will be applied: (1) High-vertical-resolution moored profiler (MP) observations of velocity and density structure in the EDW formation region, (2) Detailed Lagrangian measurements of EDW subduction, evolution and dispersal and (3) Shipboard and ARGO float observations of regional hydrographic structure. These approaches are highly complementary: the moored time series will be used to determine the mean properties and thickness of EDW at formation, while variability from this mean both at the mooring and from float data will indicate the importance of lateral eddy fluxes in the subsequent evolution and dispersal of EDW (processes unresolved by previous low-resolution float studies and climatological analyses). The combined MP and float data will provide an independent estimate of subduction rate that can be compared with the diapycnal volume flux (or transformation) rate derived from other components of CLIMODE.