

where 6 is the potential temperature. 



If a temperature/time series is taken digitally and the only 

 temperature /depth information is from measurements taken at discrete 

 depths, the usual practice is to determine vertical excursions as the 

 following finite-difference integration of (2): 



_ (Ae/At) 

 ^ " (Ae/A3) ^* ^^^ 



The vertical temperature gradient is assumed constant in the 

 neighborhood of the depth of interest. In the 1968 experiment, STD 

 casts provided a monitor of the local temperature gradient, which is 

 neither constant nor linear. 



Obviously, to achieve an exact determination of vertical excursions, 

 it would be necessary to sample continuously in time and depth; however, 

 all we could do was to average the STD data and generate the excursion 

 depth/time series by mapping the temperature measurements into the 

 assumed temperature profile. Programs to handle this mapping of data 

 are now on file at the University of Washington, Department of Oceanography. 



The major difficulty in the analysis of our data is that they 

 contain a large amount of ship-motion effects. We are currently using 

 clipping and filtering techniques in an attempt to remove the ship- 

 induced noise. 



ACKNOWLEDGMENTS 



This research has been sponsored by the National Science Foundation 

 Grant GA-1417 and by the Office of Naval Research Contract Nonr-477(37) , 

 Project NR 083 012. The observations would not have been possible 

 without the help of the U.S. Coast Guard and the U.S. Coast and Geodedic 

 Survey, both of whom contributed ship time. This is Contribution 491 

 from the Department of Oceanography, University of Washington. The 

 material discussed in this paper is unclassified. 



REFERENCES 



M. Rattray, Jr., Juraj G. Dworski, and Paavo E. Kovala, 1969. 



Generation of long internal waves at the continental slope. 

 Deep-Sea Research ^ 16 (suppl.; in proof). 



P. A. LeBlond, 1966. On the damping of internal waves in a continuously 

 stratified ocean. J. Fluid Me oh. 25:121-142. 



L. H. Larsen, 1969. Internal waves incident upon a knife-edge barrier. 

 Deep-Sea Researohy 16:415-422. 



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