Variation of surface Currents Offshore from Rayong Rivermouth from NRCT Buoy Data in 1994
May 1994 (Southerly wind), Fig. 4, the principal surface currents flow to 300° and the second maxima to 120°, with the mean speed of 11.1 cm/s.
Figure 4
August 1994 (Southerly wind), Fig. 5, the principal surface currents flow to 90° (to North) and the Slower current flow to 330°, with the mean speed of 12.3 cm/s.
Figure 5
September 1994 ((Southerly wind), Fig. 6, the principal surface currents flow to 90° and the second maxima to 300°, with the mean speed of 11.9 cm/s.
Figure 6
October 1994 (Northerly wind), Fig. 7, the principal surface currents flow to 300° and the second maxima to 90°, with the mean speed of 12.9 cm/s. This month is the transition period from Southwest monsoon to North monsoon season.
Figure 7
November 1994 (Northerly wind), Fig. 8, the principal surface currents flow to 300° and the second maxima to 120°, with the mean speed of 8.4 cm/s.
Figure 8
Summary
From the mean wind data (1981-1994) at Rayong,Lat.120 38' N,Long.1010 21'E, the Northerly winds blow from October to January, the Southerly winds blow from February to May, and the southwesterly winds blow from June to September. During North monsoon season (Nov.1994), the principal sea surface currents flow to 300° (from N) and second maxima to 120° with the mean speed of 8.4 cm/s. During the South monsoon season (March to May) the principal sea surface currents flow to 300° and second maxima to 120°, with the mean speed of 11.53 cm/s. During the Southwest monsoon season (August to September), the principal sea surface currents flow to 90° (to N), and the second maxima to 330° (August) and 300° (September), with the mean speed of 12.10 cm/s. In the transition period from N to S monsoon (February), the principal currents flow to 300°, and the second maxima to 120°, with the mean speed of 12.5 cm/s. In the transition period from S to SW monsoon, actually in June, but there is no data in June and July. In the transition period from SW to N monsoon (October), the principal currents flow to 300° and smaller second maxima to 90° (N), with the mean speed of 12.9 cm/s.
Acknowledgements
The authors would like to appreciate the kind assistance of Dr. Darasi Daorueng. Dr. Pithan Singsanae and Ms. Chinoros Booncherm (SEAWATCHTHAILAND,NRCT) for sending the current data from the buoys and Mr. Vattana Kanbua (Meteorological Department) for sending the meteorological data at Rayong.
