MELLEN: SOUND PROPAGATION IN A RANDOM MEDIUM 



Stripping region through which we progress into a region of one mode 

 propagation . 



For example, in Baffin Bay, the smallest range was 100 kilometers, 

 the largest one was 400. The sound channel filled up in mode strip 

 much before that. So we had no problems there from say 50 kilometers 

 on to 400. 



Dr. M. Schulkin (Naval Oceanographic Office): I don't consider 

 it using the same attenuation behavior if you have to take a half of 

 Thorp or six-tenths of Thorp or 0.75 of Thorp. You're not really 

 tying things down. 



Dr. Mellen: No, of course not, but these are things now that 

 can be examined. If it turns out that the Thorp coefficient is con- 

 stant in the Pacific and the Gulf of Aden and so forth, the same as 

 it is in the North Atlantic, then we are going to have a check that 

 there is something wrong with our experiments. 



Right now I say that for some reason or other there is less boron 

 absorption in the Pacific than there is in the Atlantic. I don't 

 know why. 



Dr. Schulkin: It's a hypothesis. 



Dr. Mellen: Yes. 



Dr. Schulkin: But let me check one more point. The parabolic 

 equation requires 5 log R. Is this true? The intensity varies as 

 1 over R? 



Dr. Tappert: No, there is cyclindrical spreading built in but 

 on top of that you have all other attenuation mechanisms that may 

 exist. 



Dr. Weinberg: In all of these experiments the source and the 

 receiver were very carefully placed in a well defined channel and 



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