Physical Modeling of Nutrient Upwelling

浮游植物从太阳（从上方）获得能量，从水柱（从下方）获得营养。分子扩散进行得如此缓慢，以致于光区的初级生产者将在一个远低于通过实验观察到的时间尺度内耗尽其营养资源。因此，它们必须敏感地依赖于上涌过程对营养物质的补充。在深海中有大量的营养物质储存，这是由于居住在光带的生物不断死亡和分解。因此，一个可靠的浮游植物种群动态模型必须包含上升流过程的精确物理模型。虽然这一物理组成部分的工作已由少数研究人员进行，但海洋生物学家的普遍共识是，仍有大量工作有待完成。例如，Bleck等人（1988）使用MYCOM等向垂直网格模型显示了锋面对上升流过程的重要性。对于沿海上升流，“混合”版本可能更合适。然而，物理成分必须辅以一系列生物学方面的考虑，例如硅藻对光线变化的适应性；浮游动物在限制浮游植物种群中的作用以及营养物质、浮游植物和浮游动物的流动性。这种生物成分目前超出了PI的专业领域，通过与Rosenstiel学院的Gary Hitchock博士的合作，将会建立有用的预测模型。该IGMS项目由MPS多学科活动办公室（OMA）和数学科学司（DMS）联合支持。

Phytoplankton receive energy from the sun (from above), and nutrients from the water column (from below). Molecular diffusion proceeds so slowly that primary producers in the euphotic zone would deplete their nutrient resources over a time scale which is well below what is observed through experiments. They must, therefore, depend sensitively on the replenishment of nutrients through upwelling processes. There are large nutrient stocks at depth due to the constant death and decomposition of organisms that populate the euphotic zone. Thus a reliable model of phytoplankton population dynamics must incorporate an accurate physical model for the upwelling process. While work on this physical component has been undertaken by a small number of researchers, the general consensus among ocean biologists is that considerable work remains to be done. For instance, Bleck et al (1988) have shown the importance of fronts to the upwelling process using the MYCOM isopyncnal vertical grid model. For coastal upwelling, a "hybrid" version may be more suitable. However, the physics component must be supplemented by a suite of biological considerations such as the adaptivity of diatoms to variations in light; the role of zooplankton in limiting the phytoplankton populations; and the mobilities of nutrients, phytoplankton, and zooplankton. This biological component is currently beyond the PI's realm of expertise, and it is through collaboration with Dr. Gary Hitchock at the Rosenstiel School that useful predictive models will be forged. This IGMS project is jointly supported by the MPS Office of Multidisciplinary Activities (OMA) and the Division of Mathematical Sciences (DMS).