[AOS28-P06] Tracking Experiment of adrift object using Surface Drifter in Southeast coast 2019
キーワード：Surface Drifter, Surface Current, Tidal Current, Adrift object tracking experiment, mesoscale eddies
To understand the effects of tidal current and general surface current on the travel patterns of floats around the Jeju Island and southern area of East Sea. We monitored the tracks of 15 surface drifters deployed on July 25 at the southern area of East Sea. and indentified the several main drifter tracks up to January 15, 2020. In addition, from December 3, 2019 to January 14 2020, we deployed 5 surfeace drifters near the Jeju Island.
Most drifters of 15 drifters, except for on driter(212), were moved by the well know currents of the Korea Strait, such as East Korea Warm Current(EKWC) and Offshre Branch of Tsushima Warm Current(OB), and a couple of mosescale eddied as well. Other drifter(202, 205, 206, 207, 211, 214) were entrapped by mesoscale eddy at the southern area of East Sea(offshore region from Pohang) and parts of then moved again northeastward along the OB. Particularly, drifter 202 followed by Nearshore Branch of Tsushima Warm Current(NB) passed through Tsugaru Strait after October 10, 2019, and now reached Northwest Pacific Ocean. We identified again the dominant effects of Tsushima Warm Current(TWC) at the southern area of East Sea. And, mesoscale eddies are inferred owing to various forces including wind force. On the other hand, 5 drifters deployed near the Jeju Island moved southward. It was believed to be shifted due to the northerly wind effect during the observation period.
Both results show that the influence of the wind is dominant in the surface current in the observation area. Particularly, many turning points were found during the movements. The occurrence of the turning point is thought to be attributed to the influence of the tidal current, and the rotational motion at the turning point was evident when the wind speeds were low.
Most drifters of 15 drifters, except for on driter(212), were moved by the well know currents of the Korea Strait, such as East Korea Warm Current(EKWC) and Offshre Branch of Tsushima Warm Current(OB), and a couple of mosescale eddied as well. Other drifter(202, 205, 206, 207, 211, 214) were entrapped by mesoscale eddy at the southern area of East Sea(offshore region from Pohang) and parts of then moved again northeastward along the OB. Particularly, drifter 202 followed by Nearshore Branch of Tsushima Warm Current(NB) passed through Tsugaru Strait after October 10, 2019, and now reached Northwest Pacific Ocean. We identified again the dominant effects of Tsushima Warm Current(TWC) at the southern area of East Sea. And, mesoscale eddies are inferred owing to various forces including wind force. On the other hand, 5 drifters deployed near the Jeju Island moved southward. It was believed to be shifted due to the northerly wind effect during the observation period.
Both results show that the influence of the wind is dominant in the surface current in the observation area. Particularly, many turning points were found during the movements. The occurrence of the turning point is thought to be attributed to the influence of the tidal current, and the rotational motion at the turning point was evident when the wind speeds were low.