Continental shelf waves forced by nonlinear continental shelf topography  

作　　者：FENG LiCheng CHAO JiPing 

机构地区：[1]National Marine Environmental Forecasting Center, Beijing 100081, China [2]First Institute of Oceanography, State Oceanological Administration, Qingdao 266061, China

出　　处：《Science China Earth Sciences》2012年第10期1702-1705,共4页中国科学（地球科学英文版）

基　　金：supported by National Natural Science Foundation of China(Grant Nos.40906014 and 40976015);Science Foundation for Youth of the State Oceanic Administration of China (Grant No. 2010218)

摘　　要：The characteristics of continental shelf waves forced by nonlinear continental shelf topography are studied with a shallowwater model.Results show that there are two topographic Rossby waves and two inertia gravity waves.The northward propagating topographic Rossby wave couples with the inertia gravity wave into an unstable wave in the long wave band.When the continental slope is increased,the topographic Rossby wave still couples with the inertia gravity wave into an unstable wave,but the frequency decreases.In the South China Sea(SCS),the western boundary can develop an unstable wave because of topographic forcing,nonlinear conditions,and increasing amplitude.It is possible that the unstable wave develops into a vortex.In observations,the SCS has a strong western boundary current and abundant mesoscale vortice.There is a strong relationship between the emergence,disappearance,and movement of the circulation's multi-eddy structure and the seasonal evolvement of the SCS's circulation.This article shows a possible mechanism for the formation of vortices in the SCS.The characteristics of continental shelf waves forced by nonlinear continental shelf topography are studied with a shallowwater model. Results show that there are two topographic Rossby waves and two inertia gravity waves. The northward propa- gating topographic Rossby wave couples with the inertia gravity wave into an unstable wave in the long wave band. When the continental slope is increased, the topographic Rossby wave still couples with the inertia gravity wave into an unstable wave, but the frequency decreases. In the South China Sea （SCS）, the western boundary can develop an unstable wave because of topographic forcing, nonlinear conditions, and increasing amplitude. It is possible that the unstable wave develops into a vortex. In observations, the SCS has a strong western boundary current and abundant mesoscale vortice. There is a strong relationship between the emergence, disappearance, and movement of the circulation＇s multi-eddy structure and the seasonal evolvement of the SCS＇s circulation. This article shows a possible mechanism for the formation of vortices in the SCS.

关 键 词：nonlinear continental shelf topography topographic Rossby wave unstable wave 

分 类 号：P433[天文地球—大气科学及气象学] P736.15