Temporal variation of volume transport in the Tsugaru Strait, 2; An Estimation from the ADCP observation between 2002-2004

Ito, Toshimichi ; Kawamura, Hideyuki  ; Nakayama, Tomoharu*; Shima, Shigeki*; Onishi, Mitsuyo*; Isoda, Yutaka*

During Nov. 1999-Dec. 2007, JAEA carried out an observation of the Tsugaru Strait Throghflow using a ship-board Acoustic Doppler Current Profiler with voluntary cooperation by Higashi-Nihon Ferry Co. Ltd.,. From the analysis of volume transports estimated at 20 current monitoring points, it is elucidated in the period between Apr. 2002 and Mar. 2004 that; (1) most of the transport occurred in the part of the opening mouth of the strait, (2) in the area south of the main stream, west of Shimokita Peninsular, a topographically generated returning flow system was established by the wake of Shimokita Peninsular and a part of its volume transport was expected to join together with the transport of main stream, and (3) the minimum appeared in spring while the maximum was in fall showing significant amplitude of variation with 20-30 days period. The volume transport in this period varied in the range 0.5-1.8 Sv (1 Sv = 110 m s) and the mean transport was estimated to 1.2 0.2 Sv, slightly smaller than previously reported value.