Surface Currents in the North Western Pacific From WOCE/TOGA drifters
Nikolai A. Maximenko (P.P. Shirshov Institute of Oceanology, 36 Nahimovsky Prospect. Moscow 117851, Russia)
e-mail: maximen@sio.rssi.ru
Gleb G.Panteleev (Department of Oceanography, Dalhousie University, Halifax, Canada)
e-mail: pantel@karluk.physics.mun.ca
Pearn P.Niiler (Scripps Institution of Oceanography, La Jolla, USA)
e-mail: niiler@nepac.ucsd.edu
Toshio Yamagata (Graduate School of Science, Unlversity of Tokyo, Japan)
e-mail: yamagata@geoph.s.u-tokyo.ac.jp
ABSTRACT
Mean circulation in the North Western Pacific (NWP) is studied from WOCE/TOGA SVP drifter data both to derive mean velocity field and figure out peculiarities in kinematics of some groups of trajectories. Along with detection of main oceanic currents revealed are the lack of meridional water exchange across the Kuroshio Extension (KE) and signature of westward countercurrent between KE and Subarctic Front (SF) eastward jets. Velocity field is optimized with original variational scheme.
Data
To obtain mean velocities in the upper mixed layer of the North Western Pacific (20-60｡?, 120-180｡?) we analyzed data of 296 WOCE/TOGA Surface Velocity Programme [1] Lagrangian drifters (106.8 drifter years in total), deployed in 1987-96, with a drogue centered at 15m depth. The data were quality-controlled and krigged for 6-hour intervals [2] by NOAA Atlantic Oceanographic and Meteorological Laboratory. Complete set of trajectories can be got by combining Figs. 1a and b.
