Near-inertial wave propagation between stratified and homogeneous layers: Simulating transition

Table of Links

Abstract and Intro

Data

Observations

Simulating Transition

Discussion

Conclusions and References

4 Simulating transition

Following modelling by Gerkema and Exarchou (2008), an instantaneous solution of a linear 2-D z,y flat-bottom analytic simulation of IGW-propagation using 20 vertical modes in a non-traditional approach shows propagating waves from left to right, crossing an interface between homogeneous and uniformly stratified layers (Fig. 7). A single fixed frequency of motions is used in the calculation. Here, only results are shown for near-inertial frequency vertical motions, albeit distinction is studied between just-super- and just-sub-inertial motions. Only frequencies are chosen in the range (1) that will yield free IGW-propagation in both layers. This naturally limits the frequency-range to near-inertial frequencies.

In principle, the above simulation could compare well with some of the observations of abrupt phase changes in amplitude and direction of w across abrupt changes in density, provided we can transfer [z, t] to [z, y]. However, this is not so obvious (see also Gerkema and Exarchou (2008), despite some of the similar qualitative results given above, notably the abrupt changes in phase and associated amplitude variations.