wave spectrum described in this article is an updated, dif- 

 ferent spectrum from the one in the SRI publication, ) 



'h. a. DeFarrari, J. Acoust. Soc. Am. 56, 40-46 (1974). 



'R. p. Porter, R. C. Spindel, and R. J. Jaffee, J. Acoust. 

 Soc. Am. 56, 1426-1436 (1974). 



'"W. H. Munk, J. Acoust. Soc. Am. 55, 220-226 (1974). 



"o. M. Phillips, Dynamics of the Upper Ocean {Cambridge U. 

 P., Cambridge, England, 1966). 



'^M. Milder, "Users Manual for the Computer Program 

 ZMODE," RDA-TR-2701-001, R&D Associates, Santa Moni- 

 ca, CA (July 1973). 



"m. Leontovich and V. Fok, "Solution of the problem of prop- 

 agation of electroniagnetic waves along the earth's surface 

 by the parabolic equation method," Zh. Eksp. Teor. Fiz. 

 16, 557 (1946). 



"f. D. Tappert and R. H. Hardin, in "A Synopsis of the AESD 

 Workshop on Acoustic Modeling by Non Ray Techniques, 22 — 

 25 May 1973, Washington, D. C. ," AESD TN-73-05, ONR, 



Arlington, VA (Nov. 1973). 



F. D. Tappert, "Parabolic equation method in underwater 



acoustics," J. Acoust. Soc. Am. 55, S34 (A) (1974). 



"Tt. H. Hardin and F. D. Tappert, SIAM Rev. (Chronicles) 

 15, 423 (1973); F. D. Tappert and R. H. Hardin, Proceed- 

 ings of the Eighth International Congress on Acoustics (Gold- 

 crest, London, 1974), Vol. II, p. 452. 



"We have ignored the fact that the internal waves are moving 

 slightly while the acoustic signal is propagating (due to the 

 finite speed of sound). This approximation is justified since 

 the sound travels much more than a horizontal correlation 

 distance during a time short compared to the internal-wave 

 correlation time (Kenneth M. Watson, private communica- 

 tion, 1975). 



"We are indebted to H. Brock and C. W. Spofford of the 

 Acoustic Environmental Support Detachment, ONR, for pro- 

 viding this subroutine. 



"l. Dyer, J. Acoust. Soc. Am. 48, 337 (1970). 



209 



