CMG Research: Making inferences about planktonic ecosystems with models and observations: use of emulators to make complex multidimensional applications tractable

CMG 研究：通过模型和观察对浮游生态系统进行推断：使用模拟器使复杂的多维应用程序变得易于处理

• 批准号: 0934653
• 负责人: Dennis McGillicuddy
• 金额: $ 66万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0934653&HistoricalAwards=false
• 关键词: CMG; Research; Making; inferences; about

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Emulators are computationally inexpensive representations of complex model output as a function of uncertain inputs. They provide drastic computational savings, and may thus greatly expand the possibilities for statistical inference using state-of-the-art, spatially-explicit plankton ecosystem models - yet they have never previously been utilized in this context. The multidimensional nature of plankton models requires significant extension of current emulator methods. Research in this area will therefore be entirely novel and require a close collaboration between plankton ecologists and mathematicians.The proposed research focuses on three specific applications, all of which are beyond the scope of modern computational resources without the use emulators or alternative fast approximations. First, emulators will be used to test simple plankton ecosystem models in terms of their ability to fit the Bermuda Atlantic Time Series (BATS) observations in a one-dimensional spatial setting. This problem provides an ideal testbed for developing emulator methods for multidimensional output. This will begin with an application in which the forcing is assumed to be known. In this context, the dynamical model is relatively inexpensive, allowing the inferences drawn using the emulator to be compared with those drawn using the dynamical model. The computational advantage of the emulators will then be exploited in the context of forcing that is not perfectly known, facilitating joint inference of biological processes and uncertainty in physical forcing. This will allow the investigators to address a long-standing question in plankton ecosystem modeling: How much physical and biological complexity is necessary to explain the BATS data?The second application aims to develop an emulator for a 3D plankton model of the entire North Atlantic, and use it to infer model parameter values from satellite data under the assumption of known physical forcing. This will permit inference of basin-wide seasonal variability in plankton abundance, primary production, and carbon export.Third, emulation methods will be used together with the basin-wide model to assess uncertainty in forecasts of ecosystem response for various climate change scenarios. The intellectual merit of this effort stems from an interdisciplinary approach to problems at the interface between oceanography and statistics. Conjoining of models with observations using advanced statistical and data assimilative methodologies will result in new insights into plankton ecology on local to basin scales, providing information relevant to oceanic ecosystems and global carbon cycling. In so doing, the proposed research will advance both disciplines as well as their interface.Broader impacts of this activity include training of graduate and undergraduate students as well as a postdoctoral fellow. Curricular development will include enhancement of an existing course on linking models and observations in planktonic ecosystems. The PIs also plan to produce a short text that will promote broad dissemination of this material.

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。仿真器是复杂模型输出作为不确定输入的函数的计算成本低廉的表示。它们提供了巨大的计算节省，并因此可能大大扩展使用最先进的，空间上明确的浮游生物生态系统模型的统计推断的可能性-但他们以前从未在这种情况下使用。浮游生物模型的多维性质需要显着扩展目前的仿真方法。因此，这一领域的研究将是全新的，需要浮游生物生态学家和数学家之间的密切合作。拟议的研究集中在三个具体的应用程序，所有这些都超出了现代计算资源的范围，而不使用模拟器或替代快速近似。首先，模拟器将用于测试简单的浮游生物生态系统模型在一维空间环境中拟合百慕大大西洋时间序列（BATS）观测结果的能力。这个问题提供了一个理想的测试平台，为开发多维输出的仿真器方法。这将开始与一个应用程序，其中的强迫是假定已知的。在这种情况下，动态模型相对便宜，允许使用仿真器得出的推论与使用动态模型得出的推论进行比较。仿真器的计算优势，然后将被利用的背景下，迫使这是不完全知道，促进联合推断的生物过程和物理强迫的不确定性。这将使研究人员能够解决浮游生物生态系统建模中一个长期存在的问题：解释BATS数据需要多少物理和生物复杂性？第二个应用程序的目的是开发一个模拟器的三维浮游生物模型的整个北大西洋，并使用它来推断模型参数值从卫星数据的假设下，已知的物理强迫。这将允许推断全流域浮游生物丰度、初级生产和碳输出的季节性变化。第三，仿真方法将与全流域模型一起使用，以评估各种气候变化情景下生态系统响应预测的不确定性。这一努力的知识价值来自对海洋学和统计学之间的接口问题采取的跨学科办法。使用先进的统计和数据同化方法将模型与观测相结合，将使人们对地方到流域尺度的浮游生物生态有新的认识，提供与海洋生态系统和全球碳循环有关的信息。在这样做的过程中，拟议的研究将推进这两个学科以及他们的接口。更广泛的影响，这一活动包括研究生和本科生以及博士后研究员的培训。课程开发将包括加强现有的关于将南极生态系统的模型和观测联系起来的课程。参与者还计划编写一份简短的文本，以促进广泛传播这一材料。