Marine environmental prediction through improved biogeochemical models

通过改进的生物地球化学模型进行海洋环境预测

• 批准号: RGPIN-2014-03938
• 负责人: Fennel, Katja
• 金额: $ 4.44万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=610734
• 关键词: Marine; environmental; prediction; through; improved

Anthropogenic perturbations of the global carbon and nitrogen cycles are altering fundamental physical and chemical properties of the ocean including water temperature, vertical stratification, circulation, pH, nutrient regimes and oxygen levels. It is expected that these changes in environmental conditions will strongly affect planktonic communities (which support the marine food web and play a major role in regulating the ocean’s uptake of carbon) and higher trophic level species like fish, bivalves and crustaceans (which are of commercial importance). Numerical models that accurately simulate physical, chemical and biological processes are a key tool for describing current and future environmental ocean conditions; however, a paucity of detailed ocean observations has severely limited efforts to critically evaluate models and improve their realism. To date there is no consensus on an appropriate biogeochemical model structure, and model projections of how ocean conditions will change in the coming century vary dramatically. Furthermore, model projections of future conditions (including those of the IPCC) rely on global models that lack the spatial resolution to adequately represent coastal regions (defined here to include continental shelves, i.e. regions with water depths <200m). Yet coastal processes have been shown to significantly affect global element cycles, and the coastal ocean is experiencing some of the fastest changes and is of most direct importance for human activities. The long-term objective of my research program is to develop models that better predict how natural variability, human pressures and climate change affect marine ecosystems now and in the future. The projects proposed here aim specifically at improving biogeochemical models in two key aspects: by combining models with new data streams from a range of ocean observing systems in order to improve process-level representations and parameterizations (Theme 1), and by improving the representation of biogeochemical processes in shelf regions through highly resolved regional models with dynamic benthic-pelagic coupling (Theme 2). Theme 1 takes advantage of recent progress in the development of autonomous oceanographic platforms and compact, low-cost sensors for measuring many important biological and chemical quantities in the ocean. The developments allow us to gather observations at ecologically relevant spatial and temporal scales and offer enormous potential for improving biogeochemical models. Theme 2 directly addresses a major shortcoming of current models, namely the lack biogeochemical interaction between sediments and water column. Prior research has shown that the exchange of constituents between sediments and the overlying water column is of major importance in determining productivity and environmental conditions in coastal systems unlike in the deep ocean where such exchange is weak. At present models either neglect or crudely parameterize this interaction. Biogeochemical models are and will continue to be essential tools in assessing, understanding and projecting the environmental changes affecting coastal and open ocean ecosystems. Further development of these tools is of global relevance and of strategic importance for Canada given its long coastline, its dependence on coastal resources and its commitment to implementing an ecosystem approach to ocean resource management. The program proposed here will lead to concrete model improvements.

全球碳和氮循环的人为扰动正在改变海洋的基本物理和化学性质，包括水温、垂直分层、环流、pH值、营养状况和氧气水平。预计环境条件的这些变化将强烈影响浮游生物群落（它们支持海洋食物网并在调节海洋碳吸收方面发挥主要作用）和更高营养水平的物种，如鱼类、双壳类和甲壳类（它们具有重要的商业价值）。精确模拟物理、化学和生物过程的数值模式是描述当前和未来海洋环境状况的关键工具；然而，缺乏详细的海洋观测严重限制了对模型进行批判性评估和提高其真实性的努力。迄今为止，对于一个适当的生物地球化学模型结构还没有达成共识，而且对下个世纪海洋条件将如何变化的模型预测也有很大的不同。此外，模式对未来条件的预估（包括IPCC的预估）依赖于缺乏空间分辨率的全球模式，无法充分代表沿海地区（这里定义为包括大陆架，即水深<200米的地区）。然而，沿海过程已被证明对全球元素循环产生重大影响，沿海海洋正在经历一些最快的变化，对人类活动具有最直接的重要性。