Upper Ocean Boundary-Layer Flow Determined by Dye Diffusion

Abstract

Dye patches released in the upper layer of seas indicate that the rate of increase with time of the second moments of concentration follows the Kolmogoroff's hypothesis for the inertial subrange. The curvature of dye patches photographed from the air can be explained as the vertically differential advection by the Ekman type wind‐driven currents in the upper boundary layer of the ocean. Striations of patches or plumes seem to be related to cellular motion generated by the short‐crested surface waves. The power spectra of concentration fluctuations determined across a dye plume show shift of the peak towards lower wave numbers (measured lateral to the plume) and its flattering with time. These spectral features are compared with a model similar to Heisenberg's energy transfer model by use of Kolmogoroff's energy spectrum.