SPINDEL: PHASE FLUCTUATIONS, COHERENCE AND INTERNAL WAVES 



Dr. Munk: That is a very good point, John. For those acoustic 

 measurements which sample a large depth of water column you would, 

 in fact, have a good excuse for not seeing a sharp cutoff. 



Dr. Clark: It is not sharp but there is a definite knee there 

 so you can see that. 



Dr. Munk: The other point is more serious-. I have an impression 

 that these phase and intensity fluctuations are very model-dependent 

 that no matter what kind of a model you put into the ocean, as long 

 as it is not complete nonsense, vou are going to find excellent agree- 

 ment with observations. 



I have seen this now at least in four or five different models. 



Jacobsen puts in planetary waves, and by cooking them up a little 



they show a record that he says looks like precisely the record 

 that you obtained. 



Other people like us have put in internal wave observations and 

 they look lovely. So does your group. 



And, finally, you, to make it even worse, show that under certain 

 conditions you don't need any disturbance at all. You just need 

 interference . 



I think there is a lesson to be learned there one snould face — 

 that when it comes to multipath, the statistics you get are probably 

 highly dependent on path interference and very unsensitive to the 

 ocean model itself which is good if you are an acoustician, because 

 you might get some good results without having to study the ocean. 



It is bad for us oceanographers because we are probably not going 

 to be able to use that kind of statistics ever to learn anything 

 sensible about the ocean. 



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