Regional Ecosystem & Biogeochemical Impacts of Ocean Acidification - a modelling study.

气候变化是当今时代政府和社会关注的主要问题之一。原因是工业时代人类活动排放了大量的二氧化碳（CO2），这被绝大多数科学家所接受。大气二氧化碳增加的后果之一是海洋酸化（OA）。海洋吸收了大量额外的二氧化碳，这些二氧化碳在水中发生反应，增加了酸度。这一点不太为人所知，至少在公共领域是这样，但它是建立在没有争议和被高度接受的科学理解基础上的，最近还得到了对海洋酸度增加的精确测量的证实。因此，在接下来的几十年里，海洋将受到气候变化（温度升高、环流和混合变化）和酸度增加的影响。这里就复杂了。众所周知，酸化会影响对调节海洋生态系统很重要的几个不同过程，不同物种表现出不同的敏感性。温度和洋流的变化会改变特定物种的分布，而混合率的改变（海水的搅拌）会影响基本营养物质的供应。此外，如果这些物种受到温度升高的影响，一些生理过程就更容易受到酸度的影响。海洋的酸度（或碳酸盐系统）也对温度和陆地效应（降雨变化或冰融化）做出反应，这在全球变暖的情况下很可能发生。总之，预测高CO2（气候和OA）对海洋系统的影响是一个非常复杂的问题。许多科学实验和观测项目目前正在调查气候和酸度如何影响海洋系统。然而，我们试图综合上述各种影响并对未来做出预测的唯一方法是发展数学模型。在这个提议中，我们的目标是开发现有的模型，覆盖英国周围的大陆架海洋（拥有巨大的资源利益）和北极地区（气候变化和OA迫在眉睫的风险），并提高我们对影响的规模和时间尺度的理解和确定性。我们将使用的模型系统结合了流体动力学、海洋化学和海洋生态系统及其驱动过程的代表，使其成为测试气候和OA综合效应的理想选择。这些模型将受到最新和最准确的气候变化预测的影响，我们将至少比较高排放情景（假设全球不限制二氧化碳的产生）和低排放情景（假设全球将采取重大步骤减少二氧化碳的产生）。利用实验和观测项目产生的信息，我们将改进模型中对酸度敏感的化学和生理过程的描述。通过将模型系统的后验与观测数据进行比较，我们将建立模型的准确性，并通过灵敏度分析测试单个过程或参数的不确定性。因此，我们的目标不仅是提供对未来状态的预测，还要提供对确定性的估计。对该项目将产生的影响和时间表的进一步了解将直接纳入联合王国政府的咨询进程，并为制定国家和国际缓解和适应战略提供基础。

Climate change is one of the main governmental and societal concerns of the current era. The cause, the emissions of huge quantities of carbon dioxide (CO2) by human activities during the industrial era, is accepted by the vast majority of scientists. One of the consequences of increased atmospheric CO2 is Ocean Acidification (OA). The seas absorb a significant proportion of the extra CO2 which reacts in water to increase acidity. This is slightly less well known, at least in the public domain, but is based on uncontroversial and highly accepted scientific understanding and recently verified by precise measurements of the oceans increasing acidity. So over the next few decades the oceans will be impacted by changing climate (increased temperature, changing circulation and mixing) and by increasing acidity. Here it gets complicated. Acidification is known to impact several different processes that are important in regulating the marine ecosystem and different species exhibit different sensitivities. Changing temperature and currents will cause the distributions of particular species to alter and modification of mixing rates (the stirring of the oceans waters) will impact the supply of essential nutrients. Further some physiological processes become more prone to acidity induced effects if those species are subject to increased temperature. The acidity (or carbonate system) of the oceans is also responsive to temperature and to terrestrial effects (changing rainfall or ice melt) that are likely to occur given global warming. In summary predicting the impact of high CO2 (climate and OA) on marine systems is a very complex question. Many scientific experiments and observational programmes are currently investigating how climate and acidity impact the marine system. However the only method we have for trying to synthesise the various impacts mentioned above and make predictions into the future are the development of mathematical models. Within this proposal our aims are to develop existing models that cover the shelf seas around the UK (which have huge resource benefits) and the Arctic region (which is imminently at risk to both climate change and OA) and improve our understanding and certainty of both the magnitude and timescale of impacts. The model system we will use incorporates hydrodynamics, marine chemistry and a representation of marine ecosystems and the processes that drive them, making it ideal to test the combined effects of climate and OA. The models will be forced by the latest and most accurate predictions of climate change and we will compare at least a high emissions scenario - which assumes that globally we do not restrict CO2 production, and a low emissions scenario - which assumes that globally significant steps will be taken to reduce CO2 production. Using information generated by experimental and observational programmes we will improve the description of acidity sensitive chemical and physiological processes in the model. By comparing hind-casts of the model system with observed data, we will establish the accuracy of the model and test uncertainty in individual processes or parameters by sensitivity analysis. We therefore aim to deliver not only predictions of future states but estimates of certainty. The improved understanding of impacts and timescales that this project will generate will be fed directly into the UK Government's advisory process and underpin the development of national and international mitigation and adaptation strategies.