ITR Collaborative Research: Diversity of Biogeochemical Processes: Modeling Multiple Biomes on Multiple Flow Scales in the Eastern Pacific Ocean

这个多学科研究项目将通过在太平洋的现实模型配置中整合大范围空间尺度的可变性（通过创新的嵌入式网格和先进的代码架构）和广义适应性生态食物网（通过多种浮游生物大小类别、功能群和限制营养物质）来探索和扩展信息技术能力的前沿。这种提出的元素组合是前所未有的，因此突破了模拟现实的极限。海洋环流和生物地球化学的模拟将基于区域海洋模拟系统（ROMS）的持续发展，这是一种相对较新的计算代码，具有创新的时空离散化、亚网格尺度传输参数化、开放边界条件和嵌入式网格能力。计算研究将集中在：双向嵌入和跨嵌入层的通量一致性，并行化性能和可移植性，以及代码架构的软件协议。生物成分将来自一个新的全球生态系统模型，该模型明确处理铁限制、氮固定、尺寸结构和硅藻华。该策略将以粗空间分辨率模拟整个太平洋环流和生物学（即，不解决涡旋），然后在东部边界的三个生产性区域子域（热带、亚热带和亚极地）以精细分辨率研究中尺度影响，这些子域具有独特的生物群落。将分析耦合解决方案，以确定中尺度生物-物理变异性向更大尺度的纠正，从广义的生态规则中出现不同的生物群系，以及基于信息理论模型选择技术匹配观测所需的生物复杂性水平。更广泛的影响：尽管这些研究集中在具有特定海洋行为的特定地方，但它们将为全球海洋过程提供一个通用原型，并为缩小行星尺度气候模拟以确定其区域尺度后果的重要挑战提供一个通用原型。该项目是加州大学洛杉矶分校和伍兹霍尔海洋研究所之间的多学科合作。这些人员拥有物理、生物和化学海洋学方面的专业知识，以及国家超级计算中心高端计算建模所需的算法和程序，他们将培训一名博士后和一名研究生使用这些复杂的工具。

This multidisciplinary research project will explore and expand the frontier of Information Technology capabilities by incorporating variability across a large range of spatial scales (through innovative embedded griding and advanced code architecture) and generalized adaptive ecological food webs (through multiple planktonic size classes, functional groups, and limiting nutrients) in realistic model configurations for the Pacific Ocean. This proposed combination of elements is unprecedented and thus pushes against the limits of simulating reality. The simulations of oceanic circulation and biogeochemistry will be based on the continued development of the Regional Oceanic Modeling System (ROMS), a relatively new computational code with innovative space-time discretization, sub-gridscale transport parameterizations, open-boundary conditions, and embedded griding capabilities. The computational research will focus on: 2-way embedding and flux-consistency across embedding levels, parallelization performance and portability, and software protocols for code architecture. The biological component will derive from a new global ecosystem model that explicitly treats iron limitation, nitrogen fixation, size structure, and diatom blooms. The strategy will be to simulate the entire Pacific Ocean circulation and biology at coarse spatial resolution (i.e., not resolving the eddies) and then investigate mesoscale influences at fine resolution in three productive, regional subdomains along the eastern boundary-tropical, subtropical and subpolar-with distinctive biomes. The coupled solutions will be analyzed to determine the rectification of mesoscale biological-physical variability to larger scales, the emergence of distinct biomes from a generalized set of ecological rules, and the level of biological complexity required to match observations based on information theoretic model-selection techniques. Broader Impacts: Although these studies are focused on particular places with particular oceanic behaviors, they will provide a generic prototype for oceanic processes globally and for the important challenge of downscaling planetary-scale climate simulations to determine their regional-scale consequences. This project is a multi-disciplinary collaboration between UCLA and Woods Hole Oceanographic Institution. The personnel have expertise in physical, biological, and chemical oceanography and in the algorithms and procedures required for high-end computational modeling at the national supercomputing centers and they will train a post-doc and a graduate student in using these complex tools.