|Title||Low-frequency variability of monsoon-driven circulation with application to the South China Sea|
|Publication Type||Journal Article|
|Year of Publication||2015|
|Authors||Yang H.Y, Wu L.X, Sun S.T, Chen Z.H|
|Journal||Journal of Physical Oceanography|
|Type of Article||Article|
|Keywords||boundary current; circulation; double-gyre; dynamics; instability; interannual; large-scale; multiple equilibria; nonlinear dynamics; ocean; Ocean circulation; Ocean dynamics; part i; Potential vorticity; quasi-geostrophic model; Rossby waves; variability; wind-driven|
The interannual variability of the upper-ocean circulation forced by seasonally varying monsoonal wind is investigated in a two-layer quasigeostrophic (QG) model, with the aim to understand the low-frequency variability of the South China Sea (SCS) circulation. It is demonstrated that the seasonally varying monsoonal wind can force the upper-ocean circulation with significant internal variability, which is mainly associated with the intrinsic nonlinear dynamics of the summer double-gyre system. This arises from the fact that the intrinsic variability, characterized by the Rossby wave adjustment in the winter single-gyre system, is much weaker than that in the summer double-gyre system driven by the intergyre eddy potential vorticity flux through barotropic instability.