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

与公海相比，世界沿海海洋很小，但它们贡献了50%的海洋生物生产力，是受人类影响最大的地区，也是人类使用最多的地区。与公海一样，由于包括气候变化和污染在内的人类影响，我们的沿海海洋正在经历快速变化。它们变得更温暖，更酸性，含氧量更少。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，许多最重要的问题都有更长的时间尺度。这样的问题：a)自前工业化时代以来的碳投入是否显著改变了PH值？许多贝类由碳酸钙矿物制成贝壳，随着pH值的下降，碳酸钙矿物更难生产和维护。因此，对于影响，一个相关的、更直接的问题是，碳投入是否显著改变了生产这些结构所需的能源？预计未来几十年会有哪些变化？B)鱼类产量的长期变化是否表明上个世纪初级生产力发生了变化？我们有良好的捕捞成功记录，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)随着海平面上升，我们的潮汐将如何变化？随着海平面上升，我们沿海地区的形状将发生变化，特别是狭窄的海峡和三角洲。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，我们沿海水域的氧气变化会有多大？开放海洋中氧气的减少和陆地营养盐污染的增加都会导致沿海氧气的减少，但强烈的混合程度会减缓这种增加。初级生产力的变化也可能产生协同和显著的影响。在这项提案中，我们将使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。我们将把重点放在萨利什海，那里包含各种沿海政权。我们将使用SalishSeaCast一个高分辨率的数值模式，其中包括循环、营养物质、氧气、碳、浮游植物和浮游动物。我们将专注于确定我们每一个问题的答案的具体过程，以确保准确性和提高理解。这种有针对性的缩减过程是这一研究领域的一种新技术，而不是一刀切地重建过去和预测未来。短期内，我们的目标是前两个问题的答案。这两个答案都将有助于加拿大的渔业政策(分别是贝类水产养殖和野生和养殖三文鱼渔业)，因为它们更好地定义了过去观察到的变化，并预测了我们可以预期在未来看到的变化。

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.