2010-2011년 겨울에 관측된 남중국해 비선형 내부파

Abstract

In a pilot study of nonlinear internal wave (NLIW) generation and evolution, pressure-recording inverted echo sounders were deployed in Luzon Strait and the South China Sea (SCS) during 09/2010−06/2011. Acoustic echo times at 6-second intervals were retrieved at 3 sites from November 2010 to April 2011 (two in Luzon Strait and one in the SCS). The observations reveal energetic NLIWs during the winter months, suggesting that lack of remotely-sensed NLIWs in winter is due to wind-induced surface roughness obscuring surface NLIW signals. Wave packets with relatively weak NLIWs were also observed from mid-November to mid-December 2010 and from mid-February to mid-March 2011. Comparisons with data-assimilated HYCOM outputs reveal that the weak NLIWs occurred when the Kuroshio intruded into the SCS or the weakened Kuroshio modified stratification in LS. Numerical simulations and a simplified 2-D internal wave model will be used to explore the impacts of background circulation and stratification changes on the evolution of NLIWs in the SCS.cond intervals were retrieved at 3 sites from November 2010 to April 2011 (two in Luzon Strait and one in the SCS). The observations reveal energetic NLIWs during the winter months, suggesting that lack of remotely-sensed NLIWs in winter is due to wind-induced surface roughness obscuring surface NLIW signals. Wave packets with relatively weak NLIWs were also observed from mid-November to mid-December 2010 and from mid-February to mid-March 2011. Comparisons with data-assimilated HYCOM outputs reveal that the weak NLIWs occurred when the Kuroshio intruded into the SCS or the weakened Kuroshio modified stratification in LS. Numerical simulations and a simplified 2-D internal wave model will be used to explore the impacts of background circulation and stratification changes on the evolution of NLIWs in the SCS.