GEOCHEMISTRY AND PHYSICS OF OCEAX CIRCULATION' 



307 



Table III. C^'* Results on Surface Ocean Water 



iV(?/e. Quantities in parentheses indicate number of samples. 

 " Fonselius and Ostlund, Tellus, 11, 77, 82 (1959). 

 ''Broecker c/ a/., J. Ceophys. Research, 65, 2903-2931 (i960). 



" Rafter and Fergusson, Second UN International Conference on the Peaceful Uses of 

 Atomic Energy, Vol. 18, pp. 526-532 (1958). 



dilution for the mixed layer and a somewhat smaller figure for the 

 vertically mixed reservoirs at the extremes of the ocean. Again 

 the correction is sufficiently small that it does not have a large 

 effect on any conclusions drawn. Thus the corrected values in the 

 1890 column may be taken to represent concentrations of C^'* in 

 the surface ocean prior to man's tampering with the system. 



The results suggest a difference of ~ 12 per mil between the 

 average North and South Atlantic mixed layers. The Caribbean 

 has a value intermediate between the two, as would be expected, 

 since it receives water from both the North and South Atlantic 

 mixed layers. A sharp drop in C^^ occurs on crossing the Antarctic 

 convergence. Rafter and Fergusson observe a quite similar sharp 

 drop in the South Pacific. Fonselius and Ostlund find, in contrast, 

 slightly higher values in the cold water of the northern-most 

 Atlantic. The South Pacific average is quite close to that for the 

 Atlantic. 



