Penetration of nonlinear Rossby eddies into South China Sea evidenced by cruise data

Abstract

[1] From the analyses of the cruise conductivity-temperature-depth profiler and acoustic Doppler current profiler data combined with simultaneous satellite altimeter data and Argo float profiling data, this paper provides evidence for the nonlinear Rossby eddies (NREs) penetrating through the Kuroshio and the Luzon Strait and entering the South China Sea (SCS). A high-salinity water prism in the subsurface layer west of the Luzon Strait was observed in January 2010. The salty prism centered at around 21°N and 118°E has a salinity higher than 34.8 and co-locates with an anticyclonic eddy with a diameter of about 150 km. The water properties of the salty prism are close to those of the Northwest Pacific (NWP) water. The time series of altimeter data and Argo float profiling data indicate that the anticyclonic eddy originates from an NRE that propagates westward from the NWP. The eddy penetrates the Luzon Strait at a speed of about 0.6 m s À1 because of the effects of the narrow strait and the Kuroshio-eddy interaction and carries the high-salinity subsurface water from the NWP into the northern SCS.

Mesoscale eddies in the South Atlantic Bight and the Gulf Stream Recirculation region: Vertical structure

“…Anomaly observations from Argo profiles were combined with altimetry data to reconstruct the vertical structure of eddies. The approach of combining satellite data and in situ observations from the Argo program has been widely used with great success over the last few years [e.g., Qiu and Chen , ; Chaigneau et al ., ; Chen et al ., ; Hu et al ., ; Liu et al ., ; Yang et al ., ]. All profiles in which a float surfaces inside cyclonic or anticyclonic eddies (as determined by the altimeter observations; Figure ) were transformed into an eddy‐centered coordinate system normalized by the eddy radius.…”

Intra-seasonal variability of Pacific-origin sea level anomalies around the Philippine Archipelago

“…It is still controversial as to whether sea level signals originated in the interior Pacific can penetrate the Kuroshio and propagate into the northern SCS through the Luzon Strait (Hu et al 2001(Hu et al , 2012Zhang et al 2010;Lu and Liu 2013). As will be discussed in this study, the Pacific-origin, intra-seasonal sea level signals cannot enter the eastern SCS directly through the Luzon Strait in the form of oceanic waves.…”

Seasonal thermal fronts on the northern South China Sea shelf: Satellite measurements and three repeated field surveys

“…Eddies with different horizontal scales are embedded in the circulation [ Hwang and Chen , ; Wang et al ., ; Chow et al ., ; Nan et al ., ]. External fluxes from adjacent open oceans also have significant impacts on the upper layer circulation of the NSCS via the Luzon Strait and Taiwan Strait [ Shaw , ; Farris and Wimbush , ; Qu and Lukas , ; Hu et al ., ]. As a result of wind‐forced onshore/offshore Ekman transport, the increased/decreased coastal sea surface height (SSH) compared to the outer shelf can be clearly detected from the altimetric images especially in winter/summer (Figure ), due to the shoreward piling up/offshore divergence of surface water.…”