depth. Approximately twice as many observations were available for 

 the progressive vector plots of the buoyed current meter data than 

 were available for similar plots of the anchor station observations. 

 Therefore, the progressive, vector diagrams plotted from the buoy data 

 were adjusted to the same length as those of the anchor stations in 

 order to facilitate comparison. Individual observations correspond- 

 ing in time lie approximately side by side and are connected by bro- 

 ken lines. 



Hodographs 



At each anchor station, current observations were obtained at 

 6-meter intervals between k meters and the bottom. Although each 

 vertical series required approximately one hour to complete, each is 

 treated as a quasi-simultaneous vertical velocity profile. Hodo- 

 graphic plots of several series at Stations B and C are presented in 

 Appendix E. Each plot includes the surface wind vector drawn in the 

 direction of the air movement for comparison with the surface currents. 



DISCUSSION OF RESULTS 



The three basic methods of data analysis described in the pre- 

 vious section provide significant clues to the circulation patterns 

 over Plantagenet Bank during the period of observation. The strik- 

 ing wind influence on the observed surface circulation is immediately 

 apparent from comparison of the central vector plots of wind and sur- 

 face currents at the 3 anchor stations. This effect is apparent in 

 the plots for Stations B and C, where winds blew primarily toward di- 

 rections within a 90-degree sector (01*^5° to 135°T, Appendix C) and 

 were relatively steady during the period of observation. 



In agreement with Ekman's fundamental considerations of wind- 

 driven ocean currents, the observed surface currents (Appendix C) 

 fell largely in a sector rotated '+5 degrees to the right of the 

 primary wind direction. No clear relationship was apparent between 

 winds and surface currents at Station A, since winds at this 

 station were highly variable in both direction and speed. Ane- 

 mometer wind velocities were recorded continuously at ARGUS ISLAND, 

 as well as on board the siirvey vessel. Since wind stress on the 

 sea surface is directed downwind and is approximately proportional 

 to the square of the wind velocity measured at anemometer level 

 (Sverdrup, 19*12 and Holmboe, Forsythe, and Gustin, 19^5)^ these 

 measurements are considered an index of the direction and magnitude 

 of sea surface stresses. Central vector plots with wind vectors 

 drawn in the direction of air movement may then be used to repre- 

 sent the driving force of the surface currents. 



Below the U-meter depth, currents generally veered progressively 

 toward the right, conforming to the Ekman spiral principle to depths 

 varying between 10 and 3U meters. Hodographic plots (Appendix D), have 

 been constructed for a few of the vertical series made at Stations B and C, 

 where relatively unidirectional winds of appreciable speed had blown 



