Abstract:
The purpose of this research is to study circulation patterns, and current divergence and convergence in the coastal area of Trat Province in 2018 using the Princeton Ocean Model (POM). The results showed that the circulation patterns were mainly controlled by the monsoon winds. The depth-averaged current magnitude was high in the southwest monsoon with a direction from the northwest to the southeast, and it was low in the northeast monsoon with a direction from the southeast to the northwest. The coastal area has small divergences alternating small convergence throughout the year. Large divergence and convergence were found near the north coast of the study area, and the west coast of Chang Island, Mak Island, and Kood Island. They were also found in Trat Bay but in smaller sizes. During the southwest monsoon, the current magnitude was high, and divergence/convergence appeared clearer than in the other monsoon seasons. The monsoon winds were the main factor controlling the circulation patterns, resulting in the seasonal variations of current divergence/convergence. The geographical and coastal features of Trat Province were other factors affecting circulations and current divergence/convergence. The convergence areas were found to relate to red tide and jellyfish bloom development. However, those phenomena are also controlled by other biological and physical factors.