rent. If this flow is in geostrophic balance, the 

 field of mass should slope upward toward the 

 equator from both the north and south. This 

 configuration was observed in either the 23.5 

 or 24.0 g/1 isopycnals in every one of the tran- 

 sects (figs. 4, 7, 10, 13, 16, 19 and 22), indicat- 

 ing the uniform presence of the westward flow. 



Equatorial Countercurrent 



Evidence of the presence of the eastward 

 flow of the shallow Equatorial Countercurrent 

 north of the equator was found in the vertical 

 distribution of density (isopycnals inclined 

 downward toward the south) on the three 

 EVERGREEN transects and on the third 

 (northernmost) ROCKAWAY transect (figs. 

 4, 7, 10 and 22). This current has been found 

 to be seasonally variable, and according to 

 Boisvert (1967), who worked with the histori- 

 cal ship drift data held by NODC and USNOO, 

 its maximum development in the western North 

 Atlantic occurs in August-October, and its mini- 

 mum development is in January-April. The 

 inclinations of the field of mass observed on the 

 EVERGREEN transects (February) certainly 

 do not agree with Boisvert's portrayal of the 

 current which shows it to be absent from the 

 vicinity of the transects during that period. 



South Atlantic Central Water 



Between the layer of maximum salinity at 

 about 80 to 100 meters and the layer of mini- 

 mum salinity at about 700 meters, the water 

 column transected by EVERGREEN, EAST- 

 WIND, and ROCKAWAY was composed of 

 South Atlantic Central Water. This mass, de- 

 fined by Sverdrup, et al. (1942) by an approxi- 

 mately linear T-S envelope between 6-8°, 34.2- 

 34.6°/oo and 16-18°, 35.7-36.0°/„o, is thought to 

 form at the subtropical convergence and spread 

 throughout the South Atlantic at intermediate 

 depths. 



Antarctic Intermediate Water 



The layer of minimum salinity, found 

 throughout the tropical Atlantic at about 700 to 

 900 meters, is the main characteristic of the 

 Antarctic Intermediate Water mass which 

 spreads northward in the Atlantic from the 

 Antarctic Convergence. This water wass was 

 found on all the transects (figs. 3, 6, 9, 12, 15, 

 18 and 21). Salinity values in the layer were 

 found to be lower at the shoreward end of the 

 transects (<34.5°/oo), suggesting that the 

 principal advection of Antarctic Intermediate 

 Water occurs near the continental margin, just 

 as appeared to be the case with the high salinity 

 water of the North Brazilian Coastal Current. 



REFERENCES 



Boisvert, W. E. (1967) Major currents in the North and 

 South Atlantic Oceans between 65°N and 60°S. U.S. 

 Naval Oceanographic Office Technical Report TR-193. 



Cochrane, J. D. (1963) Equatorial Undercurrent and 

 related currents off Brazil in March and April 1963. 

 Science 142(3593) :669-671. 



Cochrane, J. D. (1965) Equatorial currents of the west- 

 ern Atlantic. Progress report on ONR Contract 2119 

 (04) for 1964-65. Texas A&M University Department 

 of Oceanography and Meteorology. Ref. 65-17T. 



Cochrane, J. D. (1968) Currents and waters of the east- 

 ern Gulf of Mexico and western Caribbean, of the 

 western tropical Atlantic Ocean, and of the eastern 

 tropical Pacific Ocean. Texas A&M Technical Report. 

 6&-8T, 19-28. 



Goulet, J. R., Jr. and M. C. Ingham. (In preparation) 

 The shallow layer of high salinity in the southwestern 

 tropical Atlantic Ocean. 



LaFond, E. C. (1951) Processing oceanographic data. 

 U.S. Navy Hydrographic Office Publication No. 614. 

 114 pp. 



Metcalf, W. G. (1968) Shallow currents along the north- 

 eastern coast of South America. Jour. Mar. Res. 

 26(3):232-243. 



Metcalf, W. G. and M. C. Stalcup (1967) Origin of the 

 Atlantic Equatorial Undercurrent. Jour. Geophys. 

 Res. 72(20) :4959-4975. 



Strickland, J. D. H. and T. R. Parsons (1965) A manual 

 of sea water analysis. Bulletin No. 125. Second edition, 

 revised. Fisheries Research Board of Canada. Ottawa. 



Sverdrup, H. W., M. W. Johnson, and R. H. Fleming 

 (1942) The Oceans; their physics, chemistry, and 

 general biology. Prentice-Hall, Inc., Englewood Cliffs, 

 N.J. 1087 pp. 



U.S. Naval Hydrographic Office (1955) Instruction man- 

 ual for oceanographic observation. Second edition, 

 U.S.N.H.O. Publication 607, 201 pp. 



