Changes in coastal oceanography over decades and longer: Combining dynamics and downscaling

与公海相比，世界上的沿海海洋很小，但它们贡献了海洋生物生产力的50%，是受人类影响最大的区域，也是人类使用最多的区域。与公海一样，由于人类的影响，包括气候变化和污染，我们的沿海海洋正在经历迅速的变化。它们变得更温暖，更酸性，含氧更少。 许多沿海海洋学研究都集中在较短的时间尺度上：几天到几年。然而，许多最重要的问题有更长的时间尺度。 问题如下：A）自工业化前以来，碳的输入是否显著改变了pH值？许多贝类的壳是由碳酸钙矿物质制成的，随着pH值的降低，碳酸钙矿物质更难产生和维持。因此，一个相关的，更直接的影响问题是，碳投入是否显著改变了生产这些结构所需的能量？未来几十年预计会有哪些变化？B）在过去的世纪里，初级生产力是否发生了变化，正如鱼类生产的长期变化所表明的那样？ 我们有很好的捕鱼成功记录，但浮游植物和浮游动物的历史记录很少。 需要重建过去的水平来回答这个问题。C）随着海平面的上升，潮汐会如何变化？ 随着海平面上升，我们沿海地区的形状，特别是狭窄的海峡和三角洲，发生了变化。 这些变化将改变潮汐，从而可以增加或减少海平面上升对洪水的影响。D）随着气候变化，我们沿海沃茨的氧气会发生多少变化？开阔海洋中氧气的减少和陆地营养污染的增加都倾向于减少沿海氧气，但强烈的混合水平往往会缓和这种增加。 初级生产力的变化也可能产生协同和重大影响。 在这项提案中，我们将利用过去的信息和气候模型对未来的预测，缩小到沿海地区来解决这些问题。 沿海地区是复杂的。我们将侧重于萨利希海，其中包含各种沿海制度。我们将使用SalishSeaCast一个高分辨率的数值模型，包括循环，营养物质，氧气，碳，浮游植物和浮游动物。而不是“粗刷”过去的重建和未来的预测，我们将集中在特定的过程，确定我们的每个问题的答案，以确保准确性和提高理解。 这种有针对性的降尺度过程是该研究领域的一种新技术。在短期内，我们的目标是回答前两个问题。这两个答案将有助于加拿大的渔业政策（贝类水产养殖和野生和养殖鲑鱼渔业，分别）更好地确定是什么导致了过去观察到的变化，并预测我们可以期待看到的变化在未来。

The world's coastal oceans are small compared to the open ocean but they contribute 50% of ocean biological productivity, are the regions most influenced by humans and the regions most used by humans. As with the open ocean, our coastal oceans are experiencing rapid change due to human influences including climate change and contamination. They are becoming warmer, more acidic and less oxygenated. A lot of coastal oceanography research has focused on shorter time scales: days to years. However many of the most significant questions have longer time scales. Questions such as: A) Has carbon input since pre-industrial times significantly changed the pH? Many shellfish make their shells from calcium carbonate minerals that are harder to produce and maintain as pH decreases. Thus a related, and more direct question for impacts is, has carbon input significantly changed the energy required to produce these structures? What changes are expected in the next decades? B) Have there been changes of primary productivity over the last century as suggested by the long term changes in fish production?  We have good records of fishing success but historical records of the phytoplankton and zooplankton are sparse.  Past levels need to be reconstructed to answer this question. C) How will our tides change as sea-level increases?  As sea-level rises the shape of our coastal regions, particularly narrow straits and deltas, change.  These changes will change the tides and thus can act to increase or decrease the impact of sea-level rise on flooding. D) How much will oxygen change in our coastal waters as climate changes? Decreases in oxygen in the open ocean and increased nutrient pollution from the land will both tend to decrease coastal oxygen but strong levels of mixing will tend to moderate that increase.  Changes in primary productivity may also have synergistic and significant effects. In this proposal, we will use information from the past and projections of the future from climate models, downscaled to the coastal region to attack these questions.  Coastal regions are complex. We will focus on the Salish Sea which contains a diversity of coastal regimes. We will use SalishSeaCast a high resolution numerical model that includes circulation, nutrients, oxygen, carbon, phytoplankton and zooplankton. Rather than "broad-brush" past reconstructions and future projections we will concentrate on the specific processes that determine the answers to each of our questions to ensure accuracy and improve understanding.  This targeted downscaling process is a new technique for this research field. In the short term, our goals are answers to the first two questions. Both answers will aid Canada in fisheries policy (shellfish aquaculture and wild and farmed salmon fisheries, respectively) by better defining what has caused the observed changes in the past and by projecting the changes we can expect to see in the future.