Katie uses profiling float data and observed and modeled meteorology to study upper-ocean processes in the North Atlantic Ocean in collaboration with her advisor, John Toole. In the winter, large heat transfers from the warm Gulf Stream waters to overlying cold air masses are thought to lead to convection and the formation of a water mass known as North Atlantic Subtropical Mode Water, or Eighteen Degree Water (EDW). Katie's thesis research is aligned with a large program called CLIMODE (CLIVAR Mode water Dynamics Experiment) whose main goal is to investigate and quantify the processes that lead to EDW formation, which will lead to a better understanding of the oceanic meridional transport of heat, and thus the global climate system. Data including CTD sections, float depth profiles, surface meteorology, and SeaSoar sections were collected on two CLIMODE cruises during February and March of 2007 in the Gulf Stream region. Katie is using vertical profiles from a drifting float along with observed meteorological conditions to examine the evolution of the upper ocean during typical winter-time conditions. She is also implementing both one-dimensional and three-dimensional upper ocean models, driven with modeled meteorology data, to supplement the observational portion of her research.