Statistical analysis of Lagrangian transport of subtropical waters in the Japan Sea based on AVISO altimetry data

Sergey V. Prants, Maxim V. Budyansky, Michael Yu. Uleysky
2016 Nonlinear Processes in Geophysics Discussions  
Northward near-surface Lagrangian transport of subtropical waters in the Japan Sea frontal zone is simulated and analyzed based on altimeter data for the period from January 2, 1993 to June 15, 2015. Computing different Lagrangian indicators for a large number of synthetic tracers launched weekly for 21 years in the southern part of the Sea, we find preferred transport pathways across the Subpolar Front. This cross-frontal transport is statistically shown to be meridionally inhomogeneous with
more » ... nhomogeneous with "gates" and "barriers" whose locations are determined by the local advection velocity field. The gates "open" due to suitable dispositions of mesoscale eddies facilitating propagation of subtropical waters to the north. It is documented for the western, central and eastern gates with the help of different kinds of Lagrangian maps and verified by some tracks of available drifters. The transport through the gates occurs by a portion-like manner, i.e., subtropical tracers pass the gates in specific places and during specific time intervals. There are some "forbidden" zones in the frontal area where the northward transport has not been observed during all the observation period. They exist due to long-term peculiarities of the advection velocity field there.
doi:10.5194/npg-2016-67 fatcat:3cjsf2huczgihjj4eguznzbmvi