Pengaruh fenomena El-Nino dan La-Nina terhadap corak pasang surut di Malaysia

El Nino and La-Nina are amongst the meteorological influences that can cause significant tidal changes. Several studies on El-Nino and La-Nina have been carryout and the results showed that the phenomenon is not only affect the Tropical Pacific but it also affect other parts of the world ocean. This research was conducted to determine the effects of El-Nino and La-Nina phenomenon towards the tidal patterns on several parts of Malaysian coastlines by focusing on the difference between the predictions obtained with the actual value of tidal data and changes in the tidal constituents. In addition, this research has also established the Southern Oscillation Index (SOI) to measure the intensity of El-Nino and La-Nina, and then compared with the Mean Sea Level (MSL) to identify the relationship between El- Nino and La-Nina against towards MSL changes. Tidal data, meteorological data, tidal data processing, and calculation of the Southern Oscillation Index were implemented in this research. Processing of tidal data resulted in the MSL value, tidal constituents and tidal prediction while meteorological data were used for the calculation and establishment of SOI. The result obtained revealed that the phenomenon of El-Nino and La-Nina affect the tidal patterns especially at Kedah Pier Tidal Station, Pulau Pinang. The comparison between the average differences of tidal prediction and actual value of observation during El-Nino phenomenon is 0.120 metres, while during La-Nina is 0.080 metres. During El-Nino and La-Nina occurrence, the constituent of the annual solar and the half-year solar component shows significant changes compared to other tidal constituents. Furthermore, the MSL value decreases upon the occurrence of El-Nino and increases when La-Nina arrives. Therefore, it can be concluded that the occurrence of El-Nino and La-Nina affect the tidal changes and also the accuracy of tidal prediction. This phenomenon needs to be monitored from time to time because the El-Nino and La-Nina could lead to floods or any other natural disaster