This effort is to continue the development, testing, and application of the isopycnic coordinate model for ocean circulation studies. A series of studies will include the incorporation of mixed-layer dynamics into the model, the continuation of comparisons with other models of the wind driven circulation in the Atlantic, and the testing and development of the coupled wind driven and thermohaline driven mixed layer isopycnal coordinate model. These models will be applied to better understand and interpret the data acquired in the North Atlantic in particular, but additionally for the data acquired from the World Ocean Circulation Experiment (WOCE) in the next few years. This is the only isopycnic coordinate model being developed, and will also be used to intercompare results with more common finite difference, fixed coordinate models.