Eddy viscosity profiles and currents characterization of the bottom Ekman layer for the Western Gulf of Mexico continental shelf

Abstract

By analyzing a 4-year time series of currents and temperature from a set of moorings deployed over the Western Gulf of Mexico shelf, typical bottom Ekman layer parameters as the buoyancy frequency and bottom stress were estimated. Mean vertical structure and variance of the near-bottom currents are presented and the near-neutral stratification assumption is discussed considering what is expected from a turbulent bottom Ekman layer. Constant values for eddy viscosity (K) are obtained here from measured bottom Ekman spirals, which are further used to reproduce theoretical K profiles and the expected variability at each location. The results offer the first regional characterization of the bottom Ekman boundary layer, and are intended to serve in the calculation of mesoscale cross-shelf transport, as well as a reference to the turbulent parameters necessary in the development of benthic biogeochemical models.