Surface Winds of the Southeastern Tropical Atlantic Ocean 



By 



JOHN M. STEIGNER, Instructor 



Department of Natural Sciences 

 St. Petersburg Junior College 

 St. Petersburg, Florida 33733 



and 



MERTON C. INGHAM, Director 



Oceanographic Unit 



U.S. Coast Guard 



Washington, D.C. 20390 



ABSTRACT 



This publication presents mean monthly surface wind velocities by 5° rectangles 

 (Marsden square quadrants) for the eastern tropical Atlantic Ocean from the African 

 coastline at approximately lat 5° N to lat 20° S, and from long 15° E to long 20° W. 

 The publication is intended to serve principally as an information resource for studies 

 of air-sea interaction and related seasonal variation of the near-surface oceanic envi- 

 ronment. It can also be used to outline potential areas and seasons of fishing operations. 



INTRODUCTION 



The southeastern tropical Atlantic Ocean has 

 been the site of several recent oceanographic 

 and fishery studies which have added to the 

 knowledge of the oceanic environment and bi- 

 ota of this area. There have not been com- 

 parable meteorological investigations in the 

 area. Adequate atlases of average meteorolog- 

 ical conditions at the ocean surface exist for 

 the North Atlantic Ocean (U.S. Navy, 1955; 

 U.S. Naval Oceanographic Office, 1963), but 

 those for the South Atlantic (Supplement "C" 

 to H.O. No. 261, Naval Air Pilot West Central 

 Africa — including Cape Verde, Ascension, and 

 St. Helena Islands) are inadequate in geo- 

 graphical and temporal coverage. This pub- 

 lication was constructed to correct the inade- 

 quacy, at least for surface wind data, by 



' Contribution No. 204, National Marine Fisheries 

 Service, Tropical Atlantic Biological Laboratory, Mi- 

 ami, Fla. 33149. 



presenting mean monthly wind velocities by 5° 

 rectangles (Marsden square quadrants) for the 

 eastern tropical Atlantic Ocean south of lat 

 5° N. 



This publication is intended to serve prin- 

 cipally as an information resource for studies 

 of air-sea interaction and related seasonal var- 

 iation of the near-surface oceanic environment. 

 It is reasonable to hypothesize, for example, 

 that the seasonal variation in the surface wind 

 field is the cause of the variation of the position 

 of an oceanic front which annually ranges be- 

 tween lat 1° and 17° S. This hyiwthesis can 

 be tested by correlating the mean monthly 

 surface wind data with mean monthly sea- 

 surface temperature data for the tropical At- 

 lantic Ocean as portrayed by Mazeika (1968). 

 The relationship between the surface wind field 

 and sea-surface temperature also is relevant to 

 studies of the distribution of tuna and other 

 pelagic fishes. Fishery scientists have tried to 

 relate the distribution of tunas to the surface 



