Physical Processes and Seamount Productivity
Physical Processes and Seamount Productivity
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DOI：
10.1002/9780470691953.ch4
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发表时间：
2008-04
期刊：
影响因子：
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通讯作者：
M. White;I. Bashmachnikov;J. Arístegui;A. Martins
中科院分区：
文献类型：
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作者：
M. White;I. Bashmachnikov;J. Arístegui;A. Martins
简要回顾了发生在海底山的物理动力学，并强调了这些动力学对海底山生产力的影响。海底山的一些物理特征、分层和海洋流动条件相互作用，在海底山提供了许多不同的局部动力响应。这些包括泰勒柱或锥，密度表面的圆顶，封闭的循环细胞和增强的垂直混合。由于海洋背景流的变异性，可能局部海山动力学和由此产生的生物物理相互作用过程；也是可变的。这使得量化特定海山对冲击流态的“理想”响应变得困难。人们普遍认为，海底山的动态会产生诸如垂直养分通量和物质滞留增加等条件，从而促进生产力，从而推动更高的营养水平。然而，迄今为止，在观察中几乎没有一致的具体证据。这可能是由于不稳定的背景海洋强迫，它可能破坏“理想的”响应，例如在海底山产生的泰勒锥和环流细胞。此外，海山可能会向下游释放叶绿素等被动示踪剂，为周围海洋提供海洋生物物理斑块的来源。这种可变性给海底山的环境管理带来了挑战。
A brief review is given of the physical dynamics that occur at seamounts and the implications of these dynamics for seamount productivity highlighted. Several physical seamount characteristics, stratification and oceanic flow conditions interact to provide a number of different local dynamic responses at a seamount. These include Taylor Columns or Cones, doming of density surfaces, enclosed circulation cells and enhanced vertical mixing. Due to oceanic background flow variability, it is likely that the localised seamount dynamics, and resultant bio-physical interaction processes; will also be variable. This makes quantification of an ‘idealised’response of a particular seamount to the impinging flow regime difficult. It has been widely accepted that dynamics at seamounts generate conditions such as increased vertical nutrient fluxes and material retention, to promote productivity that fuels higher trophic levels. To date, however, there has been little consistent concrete evidence for this in observations. This is likely due to the non-steady background oceanic forcing which may disrupt the ‘idealised’response, such as Taylor Cones and circulation cells generated at the seamount. In addition, the seamount may shed passive tracers such as chlorophyll downstream, providing a source of oceanic bio-physical patchiness in the surrounding ocean. Such variability provides a challenge for the environmental management of seamounts.