SPINDEL: PHASE FLUCTUATIONS, COHERENCE AND INTERNAL WAVES 



layer. You immediately see that there is a problem when 4> is 0. 

 That is, F„ (w ) blows up. 



eg 



Dr. R. C. Spindel : We are quite aware of that. 



Dr. Flatte: Right. I am sure you are. The result of this, of 

 course, is if this layer happens to occur at the horizontal turning 

 point of the ray, then this does not apply any more because the ray 

 is actually curved. The point is, though, that the path does spend a 

 great deal more time in the layer near its turning point than in any 

 other layer that it is traversing. 



Dr. Spindel: Yes. 



Dr. Flatte: From our studies, at least in the type of profile 

 we were working with, which was quite different from considering a 

 particular layer, a factor-of-10 more time is spent in the region 

 near the upper turning point than in any other region. 



So I would be surprised if your profile was such that the effect 

 at the turning point, which has a factor-of-10 enhancement due to the 

 flatness of the ray, was unimportant compared to the region of your 

 fixed depth. 



Dr. Spindel: Yes. We're quite aware of the limitations of the 

 ray theory, and that is basically — 



Dr. Flatte: This is not a limitation of the ray theory. That 

 is, I think you could apply the ray theory with this except that the 

 result would be you would get most of your contribution from the 

 region where the ray is flat. 



Dr. Spindel: Yes, if that is the region where the internal waves 

 have their largest effect. I think they do in that portion of the 

 water column. 



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