| 摘要: |
| A semi-implicit semi-spectral hydrodynamic primitive equation model is used to study tracer diffusion in homogeneous and stratified lakes. Impulsively applied spatially uniform wind is applied in the long direction of a rectangular basin with constant depth and Lake Constance. Tracer mass is released at various locations of the free surface and its spreading under the action of dijfusion and advection is studied. We show that for homogeneous basins the tracer quickly spreads over the entire water depth. Inertial waves can also be detected in the tracer concentration. On the other hand for stratified waters the tracer mass is largely confined to the epilimnion with occasional penetration into the hypolimnion where large downwelling occurs. Here Kelvinand Poincar 'e-type wave dynamics is discernable in the tracer-concentratwn-time series, the former more conspicuously at nearshore, the latter at off-shore positions. |
| 关键词: Tracer diffusion lake circulation limnology oscillation |
| DOI：10.18307/1998.sup46 |
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| 基金项目: |
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| The Role of Advection and Stratification in Wind-driven Diffusion Problems of Alpine Lakes |
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Kolumban Hutter, Yongqi Wang
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Institute of Mechanics, Darmstadt University of Technology Hochschulstr. 1, D-64289 Darmstadt, Germany
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| Abstract: |
| A semi-implicit semi-spectral hydrodynamic primitive equation model is used to study tracer diffusion in homogeneous and stratified lakes. Impulsively applied spatially uniform wind is applied in the long direction of a rectangular basin with constant depth and Lake Constance. Tracer mass is released at various locations of the free surface and its spreading under the action of dijfusion and advection is studied. We show that for homogeneous basins the tracer quickly spreads over the entire water depth. Inertial waves can also be detected in the tracer concentration. On the other hand for stratified waters the tracer mass is largely confined to the epilimnion with occasional penetration into the hypolimnion where large downwelling occurs. Here Kelvinand Poincar 'e-type wave dynamics is discernable in the tracer-concentratwn-time series, the former more conspicuously at nearshore, the latter at off-shore positions. |
| Key words: Tracer diffusion lake circulation limnology oscillation |
