Figure 4. Sea-surface dynamic topography (dj-namic meters) relative to 1000 decibars, 2-10 April 1968. Arrows 

 denote sea-surface dynamic heights at intervals of 0.02 dynamic meters. Staffs of arrows are drawn per- 

 pendicular to imaginary line segments connecting adjacent stations; heads of arrows indicate direction of 

 geoslrophic current. Nomograph for obtaining geostrophic speed when entering with distance between 0.02 

 dynamic-meter contours assumes latitude of 45°, 



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