THE TOPOGRAPHY OF THE SEA SURFACE IN THE 

 REGION OF THE PHILIPPINES 



By Herbert W. Graham ^ 



U.S. Fish and Wildlife Service 

 Woods Hole, Massachusetts, U.S.A. 



Introduction 

 Under the Philippine Fishery Program the Fish and Wildlife Ser- 

 vice conducted hydrographic surveys of all Philippine waters during 

 the period 1917 to 1949. The Spencer F. Baird, one of the research 

 vessels engaged in this program, made intensive observations of tem- 

 perature, salinity, dissolved oxygen, and plant nutrients at the surface 

 and subsurface levels during each of the two seasons characteristic of 

 this area. Presented here are the charts showing the dynamic topography 

 a.t the surface for each season. 



Methods 

 Twenty-eight cruises (twenty of them hydrographic cruises) were 

 made during the survey. Composite charts were drawn so that each 

 chart combined data from all cruises in a particular season and year. 

 The CTuise numbers with dates are indicated on the charts. On chart I 

 are presented the results of four cruises made during the period Jan- 

 uary to June 1949. This is during the season of the northeast mon- 

 soon when the winds are predominantly from the northeast. Chart 2 

 presents the results of three cruises taken from July to October, 1949. 

 The two cruises taken during the period July to September are de- 

 finitely during the southwest monsoon. The October cruise occurred 

 during the beginning of the northeast monsoon of the winter of 1949- 

 1950, but the current pattern at that time of year can be expected to 

 rejjresent that of the preceding season. 



Discussion 



The deduction of ocean currents from dynamic computations is 



beset with many uncertainties particularly in areas where the effect of 



internal waves are pronounced (Sverdrup, et al., 194^, p. 453). In the 



present work no account has been taken of internal waves and the usual 



Publsshe;} with the permission of the Director, United States Fish and Wildlife Service. 



673 



