A propagation experiment was conducted in the South China Sea in 2014 with a flat bottom and seamounts respectively by using explosive sources. The effects of seamounts on sound propagation are analyzed by using the b...A propagation experiment was conducted in the South China Sea in 2014 with a flat bottom and seamounts respectively by using explosive sources. The effects of seamounts on sound propagation are analyzed by using the broadband signals. It is observed that the transmission loss （TL） decreases up to 7 dB for the signals in the first shadow zone due to the seamount reflection. Moreover, the TL might increase more than 30 dB in the converge zone due to the shadowing by seamounts. Abnormal TLs and pulse arrival structures at different ranges are explained by using the ray and wave theory. The experimental TLs and arrival pulses are compared with the numerical results and found to be in good agreement.展开更多
On the basis of scaling analysis,this paper presents a frontal geostrophic dynamic system which canbe used to describe the dynamics of an isolated bottom eddy and shows that five possible dynamicsubregimes are include...On the basis of scaling analysis,this paper presents a frontal geostrophic dynamic system which canbe used to describe the dynamics of an isolated bottom eddy and shows that five possible dynamicsubregimes are included in the system.A particle-in-cell method is used to investigate the behavior of the eddy in the two dynamic subregimes,with 1)nonlinear effect（ε）relevant to the sloping bottom-inducedbeta effect（β<sub>1</sub>）and 2)seamount-induced beta effect（β<sub>2</sub>）dominant.In the dynamic subregime of β<sub>1</sub>～ ε～10<sup>-2</sup>and β<sub>2</sub>=0,the eddy can keep as a whole for a long time and migrates for a long distance.Inthe dynamic subregime where the seamount-induced beta effect (β<sub>2</sub>～10<sup>-1</sup>)is dominant,the seamounttraps the water particles,causing the eddy to break up into a discrete set of eddies moving around the seamount.展开更多
基金Supported by the National Nature Science Foundation of China under Grant Nos 11434012 and 11174312
文摘A propagation experiment was conducted in the South China Sea in 2014 with a flat bottom and seamounts respectively by using explosive sources. The effects of seamounts on sound propagation are analyzed by using the broadband signals. It is observed that the transmission loss （TL） decreases up to 7 dB for the signals in the first shadow zone due to the seamount reflection. Moreover, the TL might increase more than 30 dB in the converge zone due to the shadowing by seamounts. Abnormal TLs and pulse arrival structures at different ranges are explained by using the ray and wave theory. The experimental TLs and arrival pulses are compared with the numerical results and found to be in good agreement.
文摘On the basis of scaling analysis,this paper presents a frontal geostrophic dynamic system which canbe used to describe the dynamics of an isolated bottom eddy and shows that five possible dynamicsubregimes are included in the system.A particle-in-cell method is used to investigate the behavior of the eddy in the two dynamic subregimes,with 1)nonlinear effect（ε）relevant to the sloping bottom-inducedbeta effect（β<sub>1</sub>）and 2)seamount-induced beta effect（β<sub>2</sub>）dominant.In the dynamic subregime of β<sub>1</sub>～ ε～10<sup>-2</sup>and β<sub>2</sub>=0,the eddy can keep as a whole for a long time and migrates for a long distance.Inthe dynamic subregime where the seamount-induced beta effect (β<sub>2</sub>～10<sup>-1</sup>)is dominant,the seamounttraps the water particles,causing the eddy to break up into a discrete set of eddies moving around the seamount.
