The Diffusion Coefficient of Seawater in Ao Si Racha

Abstract

The diffusion coefficient of seawater was calculated by using the statistical procedure of periodicity of the tidal current data. When the autocorrelation coefficient became insignificantly different from zero after some time lag, the estimate of diffusion coefficient of seawater was straightforward. The observed velocities of seawater every 10 minutes had been carried out by using SD 6000 current meter 2 meters below sea surface at Ao Si Racha for 20 days (100°55′00″E, 13°11′08″N or 707750E, 1458474N) in October 2004, May 2005 and September 2005. The order magnitude of the diffusion coefficient of seawater in East-West and North-South direction at Ao Si Racha were in the range of 0.3-1.8 m²/sec. The diffusion coefficient of seawater along the North-South direction was higher than in the East-West direction which agreed well with the stronger tidal current condition in the North-South direction.