引用本文: | 焦春萌,熊谷道夫.日本琵琶湖中内波的垂直构造.湖泊科学,1998,10(1):11-22. DOI:10.18307/1998.0103 |
| Jiao Chunmeng,Michio Kumagai.Vertical Structure of Internal Waves in Lake Biwa, Japan. J. Lake Sci.1998,10(1):11-22. DOI:10.18307/1998.0103 |
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摘要: |
在实施一十大型国际合作项目(BITEX'93)期间,作者在琵琶湖进行了一个大规模的内波野外观测9台垂直系留的潮流观测及其旋转谱分析的结果表明:除了众所周知的开尔文波以外,在表层有风的日变化造成的周期为24h的顺时针旋转的强迫振荡在温跃层.Pomcare波的第一调式(mode)占主导地位.Poincare波使温跃层附近的潮流以周期16-18h顺时针旋转在底层,周期为11h的不旋转的重力波非常明显以上结果表明,在垂直方向的不同水层占主导地位的内波是不同的.利用潮流的观测来研究内波的周期变化是一个根重要的方法.该方法可以把Poincare波从重力披中区分出来地转效应是导致流场及风场旋转的根本原因.因此,控制该湖成层期内波的主要动力过程可归结为:风应力、成层、地转效应及湖岸制约. |
关键词: 琵琶湖 内波 流场观测 垂直构造 |
DOI:10.18307/1998.0103 |
分类号: |
基金项目:BITEX'93资助项目 |
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Vertical Structure of Internal Waves in Lake Biwa, Japan |
Jiao Chunmeng, Michio Kumagai
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Lake Biwa Research lnstitute, 1-10 Uchidehama, Otsu, Shiga 520, Japan
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Abstract: |
Field observations on internal waves in the North Basin of Lake Biwa were carried out during Biwako Transportation Experiment (BITEX'93). Rotary spectrum analyses of current show that beside the fundamental internal Kelvin waves, in the top epilimnion, there were waves rotating clockwise witb a period of 24h wbieh are thought to be wind-induced oscillations. In the tbermocline, pure Poincare waves of their first mode were found, which were the governing mode at the depth. The Poincare waves made the current at that depth rotate clockwise with a period of 16-18h. In (he hypolimnion bottom, seiehes with a period of 11 h were found which were not rotating and purely gravitational. All of these illustrate that there are different kinds of governing internal waves In different vertical zones. Internal wave research by current measurement, an important method, can distinguish the Poincare waves from internal seiches. The earth rotation effects are responsible for the current rotation, as well as wind rotation phenomena. Thus, the important physical factors on internal wave dynamics during stratification period in the lake seem to he wind stress stratification, Coriolis force and shore constrained. |
Key words: Lake Biwa internal waves current measurement vertical structure |