Abstract : The long-term goal of this research is to identify and understand the mechanisms that determine the features of stratification and motion in the upper 200 meters of mid-latitude oceans. This is the depth range over which surface fluxes of momentum and buoyancy have direct influence. Our interest is in the processes by which shear and stratification interact to change upper ocean structure. Our objective in this project is to use moored array records we have produced in various observational programs in both the upper ocean and near-topography environments to produce statistical descriptions of flow that can be compared with models. Our approach is to make moored observations at a variety of locations to be able to describe coherent patterns of variability based on a number of realizations of oceanic processes. In our upper ocean work, we have been using C. S. Draper Laboratory Profiling Current Meters (PCMs) to gather moored array time series of current, temperature, and salinity profiles from about 200 to 20 m depth. Our most recent observations come from a sequence of two 6-month PCM deployments in the Arabian Sea as part of a 5-mooring year-long upper ocean array to study upper ocean response to monsoon forcing. The observed annual cycle suggests that the processes of advection, convection, surface heating, and mechanical mixing each dominate upper ocean structure over the sequence of the four seasons, respectively. The goal of ongoing analysis is to quantify these processes using an inverse analysis and data assimilation techniques.