Meso-scale eddy in the South China Sea simulated by an eddy-resolving ocean model

Abstract

Mesoscale eddies (MEs) in the South China Sea (SCS) simulated by a quasi-global eddy-resolving ocean general circulation model are evaluated against satellite data during 1993–2007. The modeled ocean data show more activity than shown by the satellite data and reproduces more eddies in the SCS. A total of 345 (428) cyclonic eddies (CEs) and 330 (371) anti-cyclonic eddies (AEs) generated for satellite (model) data are identified during the study period, showing increase of ~24% and ~12% for the model data, respectively. Compared with eddies in satellite, the simulated eddies tend to have smaller radii, larger amplitudes, a slightly longer lifetime, faster movement and rotation speed, a slightly larger nonlinear properties (U/c) in the model. However, the spatial distribution of generated eddies appears to be inhomogeneous, with more CEs in the northern part of SCS and fewer AEs in the southern part. This is attributed to the exaggerated Kuroshio intrusion in the model because the small islands in the Luzon Strait are still not well resolved although the horizontal resolution reaches (1/10)°. The seasonal variability in the number and the amplitude of eddies generated is also investigated.