Currents : South-west Monsoon 



At the Surface (Chart 5). — The dynamic topography for the Sulu 

 Sea during the south-west monsoon is shown in Charts 5-7. Chart 5 

 presents the dynamic height anomalies for the surface relative to the 

 800-decibar surface. Although the current pattern has changed since 

 the first survey, the two large eddies — the anticyclonic North Central 

 Eddy and the cyclonic South Central Eddy — still dominate the pattern. 

 The small anticyclonic eddy south of the South Central Eddy which 

 occurred during the north-east monsoon persists during the south-west 

 monsoon, but the two eddies to the north have disappeared. 



The outstanding feature of the surface currents during the south- 

 west m.onsoon is a flow of water from the China Sea between Palawan 

 and Borneo. This water travels northeastward off the coast of Palawan. 

 The fate of this water northward is uncertain. Probably part of it 

 continues northward while another part turns south as part of the 

 North Central Eddy. Another part of the south China Sea water turns 

 southward as part of the South Central Eddy, and probably continues 

 into the Celebes Sea through Sibutu Passage. The westerly current 

 coming in from the Mindanao Sea and across the central Sulu Sea has 

 much the same course as during the north-east monsoon until it meets 

 the current from the China Sea, when it turns southward as part of the 

 South Central Eddy. The strength of the surface current entering 

 frdm the Mindanao Sea is much less during the south-west monsoon 

 than during October and December. 



At 100 Metres (Chart 6). — At the 100-decibar surface relative to 

 the 800-decibar surface the South Central Eddy dominates the picture. 

 The north-easterly current off Palawan is scarcely evident. Since the 

 sill depths between Palawan and Borneo are less than 100 metres no 

 water can enter at this level, and this probably explains the absence 

 of an appreciable current off Palawan. 



' There seems to be little or no water entering from the Mindanao 

 Sela at this level. The westerly central current is weak and consists 

 actually of part of the South Central Eddy and the weak North Central 

 Eddy. To the north there seems to be a transport of water eastward, ' 

 but there are not sufficient stations in this area to indicate the flow 

 accurately. In the south-eastern part of the Sulu Sea there are two 

 snlall eddies, both of which were indicated at the surface. They are 

 probably related to a com.plex interchange of water between the Sulu 

 Sea and the Celebes Sea through the Sulu Archipelago. 



At 200 Metres (Chart 7).—kt the 200-decibar surface relative to 

 the 800-decibar surface for the south-west monsoon the conditions are 

 relatively uniform. There is a slight persistence of the South Central 

 Eddy, but the indications of currents are negligible. Again there are 

 not sufficient stations to the north to interpret the significance of the 

 indications of an easterly current off Panay. 



Temperature : North-east Monsoon 



At the Surface (Chart 8). — When the north-east half of the Sulu 

 Sea was surveyed in October the surface temperatures were mostly 

 between 29-0° c. and 30-0° c, with the highest temperature near the 

 central part of the sea. 



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