[A-CG45] [EE] 熱帯インド洋・太平洋におけるマルチスケール大気海洋相互作用

[ACG45-11] Structure and Variability of the North Equatorial Current/Undercurrent from Mooring Measurements in the Western Pacific

*Linlin Zhang¹、Dunxin Hu¹ (1.Institute of Oceanology, Chinese Academy of Sciences)

The mean structure and variability of the North Equatorial Current/Undercurrent (NEC/NEUC) are investigated with 1-year Acoustic Doppler Current Profilers measurements from 4 subsurface moorings deployed at 10.5ºN, 13ºN, 15.5ºN, and 18ºN along 130ºE in the western Pacific. The strong westward flowing NEC ranges from the sea surface down to 400 m, and the mean zonal velocity of the NEC at 10.5ºN is around -30 cm/s at the depth of 60 m. Eastward flowing NEUC jets are detected below the NEC at 10.5ºN and 13ºN, and the depth of the NEUC could reach at least 900 m. The mean velocity of the NEUC is around 4.2 cm/s at 800 m. No eastward undercurrents is observed at 15ºN and 18ºN. The mooring measurements also reveals a strong intraseasonal variability of the currents at all 4 mooring sites, and the period is around 70-120 days. The vertical structure of this intraseasonal variability varies at different latitudes. The variability of the NEUC jets at 10.5ºN and 13ºN appears to be dominated by subthermocline signals, while the variability of the currents at 15.5ºN and 18ºN is dominated by surface-intensified signals.