U. S. NAVY CONTRIBUTIONS TO THE STUDY OF 

 PACIFIC CIRCULATION 



By John Lyman 



Division of Oceanography 



U. S. Navy Hydro graphic Office, Washington, D. C, U.S.A. 



The U. S. Navy has participated in several different ways in the 

 study of Pacific circulation. The Hydrographic Office, serving as the 

 national repository of information submitted by cooperating observers 

 on merchant vessels of many different nationalities, has for half a cen- 

 tury collected the current observations of navigators, obtained by com- 

 parison of celestial fixes with dead-reckoning positions. These obser- 

 vations up to the year 1935, reduced to punched cards, have served as 

 the basic materials for the preparation of Hydrographic Office Publica- 

 tions Nos. 568, 569, and 570. Figure 1 is a sample of the data presented 

 in H. O. Pubs. No. 569 and 570, which give not only vector resultant 

 currents for each month for each 1° quadrangle but also the frequency 

 distribution of set and predominant drift for somewhat larger sub- 

 divisions. 



Observations from 1935 to 1945 have been tabulated and are on 

 file at the Hydrographic Office, while records since 1945 are awaiting 

 punching. 



Cooperating mariners in the Pacific also participate in current 

 studies by throwing over bottle papers (Fig. 2). Captain E. R. Johanson 

 of the Matson Navigation Company of San Francisco has taken an 

 especial interest in this subject in recent years, and his name appears 

 frequently in the lists of recoveries, which have been regularly reported 

 in the weekly Hydrographic Bulletin. These bottle drifts, while of 

 course they yield no direct evidence as to the precise route travelled by 

 a drifting object between the points of release and recovery, never- 

 theless are valuable in giving general circulation patterns and minimum 

 values of the set of surface currents. They are particularly useful in 

 forecasting drifts of 'vvreckage and floating mines, 



A study of local circulation at Guam in 1949 made by naval 

 authorities for planning sewer outfall locations by releasing a number 

 of drift bottles, yielded unexpected results when several bottles turned 

 up at Talaud and others in the Philippines and Japan (Hydro. Bulletin 

 of 7 April 1951). 



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