The dispersion of surface contaminants by Stokes drift in random waves
-
摘要: 漂浮于自由水面的污染物的的迁移、扩散会受到天然随机海浪的影响。之前的研究(以Herterich和Hasselmann(1982)为代表)普遍认为,随机波浪作用下的斯托克司漂移速度会引起水面污染物的离散,这个离散甚至有可能跟风和海流引起的离散同一量级。本研究就随机波浪作用下的斯托克司漂移速度是否会引起水面漂移物的离散进行理论和试验探讨。从理论推导可知,随机波浪下的质量输移速度是个定常分量,因此它不会随时间变化而引起水面漂移物的离散。随后我们在实验室水槽中进行了漂移物在随机波浪(P-M谱)作用下的漂移过程的测量。试验结果也印证了随机波浪作用下的斯托克司漂移速度不会引起水面漂移物离散的结论。Abstract: Contaminants that are floating on the surface of the ocean are subjected to the action of random waves. In the literature, it has been asserted by researchers that the random wave action will lead to a dispersion mechanism through the induced Stokes drift, and that this dispersion mechanism may have the same order of significance comparable with the others means due to tidal currents and wind. It is investigated whether or not surface floating substances will disperse in the random wave environment due to the induced Stokes drift. An analytical derivation is first performed to obtain the drift velocity under the random waves. From the analysis, it is shown that the drift velocity is a time-independent value that does not possess any fluctuation given a specific wave energy spectrum. Thus, the random wave drift by itself should not have a dispersive effect on the surface floating substances. Experiments were then conducted with small floating objects subjected to P-M spectral waves in a laboratory wave flume, and the experimental results reinforced the conclusion drawn.
-
Key words:
- dispersion /
- surface contaminants /
- random wave /
- Stokes drift
-
Buick J M, Morrison I G, Durrani T S, et al. 2001. Particle diffusion on a three-dimensional random sea. Experiments in Fluids, 30(1):88-92 Craig P D, Banner M L. 1994. Modeling wave-enhanced turbulence in the ocean surface layer. Journal of Physical Oceanography, 24(12):2546-2559 Dean R G, Dalrymple R A. 1991. Water Wave Mechanics for Engineers and Scientists. Singapore:World Scientific Publishing Giarrusso C C, Carratelli Pugliese E, Spulsi G. 2001. On the effects of wave drift on the dispersion of floating pollutants. Ocean Engineering, 28(10):1339-1348 Göda Y. 2010. Random Seas and Design of Maritime Structures. 3rd ed. New Jersey:World Scientific Publishing Company, 416-479 Herterich K, Hasselmann K. 1982. The horizontal diffusion of tracers by surface waves. Journal of Physical Oceanography, 12(7):704-711 Huang Chuanjian, Qiao Fangli, Wei Zexun. 2013. Effects of the surface wave-induced mixing on circulation in an isopycnal-coordinate oceanic circulation model. Acta Oceanologica Sinica, 32(5):7-14 Longuet-Higgins M S. 1952. On the statistical distribution of the height of sea waves. Journal of Marine Research, 11(3):245-266 Maksimenko N A. 1990. Comparative analysis of Lagrangian statistical characteristics for synoptic-scale currents in hydrophysical study areas. Oceanology, 30(1):5-9 Mantovanelli A, Heron M L, Heron S F, et al. 2012. Relative dispersion of surface drifters in a barrier reef region. Journal of Geophysical Research, 117(C11):C11016 Mesquita O N, Kane S, Gollub J P. 1992. Transport by capillary waves:fluctuating stokes drift. Physical Review A, 45(6):3700-3705 Pugliese Carratelli E, Dentale F, Reale F. 2011. On the effects of wave-induced drift and dispersion in the deepwater horizon oil spill. In:Liu Yonggang, Macfadyen A, Ji Zhengang, et al., eds. Monitoring and Modeling the Deepwater Horizon Oil Spill:A Record-Breaking Enterprise. Geophysical Monograph Series. Washington, DC:American Geophysical Union, 197-204 Sanderson B G, Pal B K. 1990. Patch diffusion computed from Lagrangian data, with application to the Atlantic equatorial undercurrent. Atmosphere-Ocean, 28(4):444-465 US Army Corps of Engineers. 2002. Coastal Engineering Manual. USACE Publications, Philadelphia, US
点击查看大图
计量
- 文章访问数: 796
- HTML全文浏览量: 30
- PDF下载量: 586
- 被引次数: 0