Perhaps I should mention that there is ART data 

 available to cover the drogue locations during the period 

 of their drifting, so that we can estimate whether the 

 surface temperatures were drifting in the same way as 

 were the surface velocities. 



We have some other data on internal waves [Refs. 6 and 

 7] that were taken in the Strait of Gibraltar [pig. 12]. 

 \ thermistor chain and recording system [Fig. I3] were 

 nung from an anchored sub-surface buoy, instead of from a 

 surface buoy, in an attempt to eliminate the effects of 

 surface waves. The very nice data obtained [Fig. I4J 

 shows a very clear thermocline that is destroyed by 

 internal waves and more or less re-established at a new 

 depth only 100 minutes later. These quickly starting 

 and quickly stopping internal waves do not exactly fit 

 the classical picture of progressive waves! Just what 

 picture they d^ fit is not yet clear, but at least the 

 data necessary to provide the picture are beginning to 

 accumulate"". 



Looking backwards at these five MILOC's, we feel that 

 much information and experience has been obtained, 

 particularly when the cruise was designed with a specific 

 or operational goal in mind, and it seems to us that the 

 scientific goals have inspired more interest, co- 

 operation, preplanning, and postprocessing speed than 

 have the operational goals. (in this context an 

 operational goal might be, for example, the hydrographic 

 surveying of a particular region for classic purposes 

 and by classic methods) . 



We want our MILOC's to be relevant to our mission as 

 a research center and to our multinational sponsorship, 

 and we want our MILOC's to be successful — that is, we 

 wish to plan a MILOC with a specific goal as its reason 

 for being, and we want that goal to be relevant to the 

 ASW problems that are the reason for our existence. 



To further this end, the Director of SACLANTCEN has 

 initiated a study exercise that is designed to re-assess 

 the nature of the environmental problems related to sonar 

 performance, to up-date our philosophies if need be, and 



See also Ref. 8 for some interesting looks at 

 sound velocity profiles and ray tracing diagrams 

 through internal waves. 



68 



