The South China Sea (SCS) circulation in its southern region in the area between Peninsular Malaysia and East Malaysia was studied from the OCCAM (Ocean Circulation and Climate Advanced Modelling). This research aimed to illustrate the general overview of the seasonal surface current circulation and the surface temperature profile which are lacking in the region. The current along the Malaysia coast flows northward in the southwest monsoon and move in opposite direction in northeast monsoon with the maximum speed of 0.4 m/s and 1 m/s, respectively. While the current flows southward, the cooler water is transported into the region which reduces the temperature at the central of the basins nearly 3 °C. The study manages to analyse the importance of the monsoonal system on the region circulation and temperature distribution.
Oceanographic cruises in Pahang water in October 2003 and April 2004, monsoon transition months, produce data on water characteristics. The temperature in both months showed higher values in nearshore compared to the offshore stations. The nearshore salinity in both months is lower than offshore stations. Comparatively, there were smaller differences in temperature and salinity in October than in April, with very little variation between nearshore and offshore stations. T-S diagram showed significant differences between October and April water characteristics. According to the water characteristic observations, the temperature and salinity in October was lower than in April, while dissolved oxygen was higher than in April. The lower temperature and salinity taken during the sampling time in October suggested that during this time, the study area already received the influences of strong winds due to upcoming monsoon. The warmer and saltier water obtained in April showed that during this time, the study area was influenced by southwest monsoon. Winds related to rainfall were observed to have impact to the dynamics of water characteristics during both months.