Application of the EA model to the velocity transversal space-time cross-correlation functions measured in the ocean

The elliptical approximation (EA) model is an important method for deducing spatial fluctuations from the temporal fluctuations at a single point. It has been extensively examined and used in shear fields of desktop experiments for the longitudinal space-time cross-correlation functions C(r, τ). Here we examine the EA model in the flow field of the ocean and present its application to the transversal space-time cross-correlation functions G(r, τ). The result shows that EA model is valid for the velocity field of the ocean, that is, G(r, τ) has the scaling form of G(r_E, 0) with r_E=[(r−Uτ)2+(Vτ)2]^1/2, where U and V are the velocities associated with the vertical phase velocities of the internal waves. Based on the EA model, we can obtain the vertical wavenumber energy spectrum of the ocean and estimate the transversal Taylor micro-scale and Reynolds number.