A gas-exchange experiment was performed using the dual tracer,3He and SF 6,method for a period of 5 days between August 12 and 17,2004,in a tidal coastal ocean located off the southern coast of Korea (34.47oN and 127.55oW).Within the study site,the water depth is approximately 30 m and the mean difference in water level between the flood and ebb tides is approximately 2 m.Over the study period,the hourly mean wind speeds (U 10 ) within the study site ranged from 0.4 to 7.5 m s-1,with a mean value of 3.9 m s-1.