We will examine EDW formation and its impact on the overall dynamics of the ventilated thermocline in a sequence of hydrostatic and non-hydrostatic modeling studies using the MIT general circulation model. The long-range objectives of this work includes assimilation in nonlinear environments and the use of extreme resolutions in non-hydrostatic calculations.
The CLIMODE modeling components are designed to address several objectives. First, by their nature, the observations will provide detailed, but incomplete samplings of the turbulent, time-dependent EDW production. Models are needed to draw together the various observations into a single, dynamically coherent framework. This is the primary objective of the regional/Gulf Stream modeling, which will result in an assimilative regional model. We also plan a sequence of more idealized, hydrostatic and nonhydrostatic experiments to provide detailed examinations of convection along the energetic rim of a basin recirculation. Given short convective timescales, such events should not be sensitive to the idealizations, and thus a numerical framework for the interpretation of field data will result. Other applications will address dynamical consequences of EDW formation and variability. With regards to these broader issues, mode water generation represents a potential vorticity input into the subsurface, adiabatic interior that the background mesoscale turbulence must contend with. In so dispersing this water along isopycnals, the larger scale flow will be shaped. Ultimately the large-scale flow will set the basic framework in which new EDW is formed and, from the intrinsic variability of the circulation, low frequency variability ocean-atmosphere heat exchange will result. Last, our modeling strategy for CLIMODE is address the following two processes: