mCDR 2023: Multiscale observing system simulation experiments for iron fertilization in the Southern Ocean, Equatorial Pacific, and Northeast Pacific

mCDR 2023：南大洋、赤道太平洋和东北太平洋铁肥化多尺度观测系统模拟实验

• 批准号: 2333334
• 负责人: Dennis McGillicuddy
• 金额: $ 48.25万
• 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: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2333334&HistoricalAwards=false
• 关键词: mCDR; 2023; Multiscale; observing; system

In order to combat the expected impacts of climate change, active removal of carbon dioxide from the atmosphere is needed in addition to emissions reductions. There is a growing consensus that at least some of society’s needs for carbon dioxide removal (CDR) will have to come from the ocean. Iron fertilization of natural phytoplankton populations is among the more promising means for ocean-based CDR, yet key questions remain, including: How effective is it? How long will the carbon be sequestered? How can we measure it? What are the intended and unintended consequences to marine ecosystems? Past ocean iron fertilization experiments have provided important information about short-term responses, but most studies were not long or large enough to measure an increase in carbon flux to the deep sea. To address the questions needed to design larger and longer field trials, this project will use ocean models to run Observing System Simulation Experiments (OSSEs) in three key regions of the ocean that are seen as likely targets for iron fertilization: the Southern Ocean, the Equatorial Pacific, and the Subarctic Pacific. Broader impacts include benefits to society via improved understanding of key physical and biological processes relevant to earth’s climate, and support of students in the research. This project is being jointly supported by the National Oceanic and Atmospheric Administration, through the National Oceanographic Partnership Program.The OSSEs will be based on two state-of-the-art global ocean biogeochemical models with eddying (0.1-0.125°) resolution: the NCAR Community Earth System Model with the Marine Biogeochemistry Library (CESM-MARBL) and the GFDL Modular Ocean Model 6 with the Carbon, Ocean Biogeochemistry and Lower Trophics model (MOM6-COBALT). High resolution nested Regional Ocean Modeling System (ROMS) models will be embedded within both global models to provide realistic representation of the energetic eddies and fronts characteristic of the three regions of interest. This “ensemble” of two parent models will allow the team to assess the sensitivity of the results to the underlying biogeochemical formulation. Far-field effects of the limited-area iron fertilization experiments will be assessed with analogous limited-area fertilization experiments in the global models. Additional runs of the global models with fertilization over large areas of the target HNLC regions will address the efficacy of iron enrichment at scale, facilitating OSSEs for a global observing network. These global ocean-only simulations run for as long as practical (30 years). To address the long-term efficacy and effects of regional iron fertilization at the scale of gigatons of carbon per year, fully coupled earth system models (ESM4 at GFDL and CESM2 at NCAR) will be run for 100 years at coarse resolution.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

为了应对气候变化的预期影响，除了减少排放外，还需要从大气中积极清除二氧化碳。越来越多的人认为，至少社会对二氧化碳清除（CDR）的一部分需求将来自海洋。自然浮游植物种群的铁施肥是海洋CDR的更有前途的手段之一，但关键问题仍然存在，包括：它的有效性如何？碳会被封存多久？我们如何衡量它？对海洋生态系统的预期和非预期后果是什么？过去的海洋铁施肥实验提供了关于短期反应的重要信息，但大多数研究都不够长或大到足以测量深海碳通量的增加。为了解决设计更大和更长的现场试验所需的问题，该项目将使用海洋模型在海洋的三个关键区域进行观测系统模拟实验（OSSE），这些区域被视为铁施肥的可能目标：南大洋，赤道太平洋和亚北极太平洋。更广泛的影响包括通过提高对与地球气候相关的关键物理和生物过程的了解以及对学生研究的支持来给社会带来好处。该项目由美国国家海洋和大气管理局通过国家海洋学合作伙伴计划共同支持。（0.1-0.125°）分辨率：NCAR社区地球系统模式与海洋生物地球化学库（CESM-MARBL）和GFDL模块化海洋模型6与碳、海洋生物地球化学和低营养层模型（MOM 6-COBALT）。高分辨率嵌套区域海洋模拟系统模型将嵌入这两个全球模型，以提供三个感兴趣区域的高能涡旋和锋面特征的真实表现。这两个母体模型的“集合”将使研究小组能够评估结果对潜在地球化学制剂的敏感性。有限区域铁施肥试验的远场效应将通过全球模式中类似的有限区域施肥试验进行评估。在目标HNLC区域的大面积施肥的全球模型的额外运行将解决大规模铁富集的功效，促进全球观测网络的OSSE。这些全球海洋模拟运行的时间与实际情况一样长（30年）。为了解决区域铁施肥在每年十亿吨碳规模的长期功效和影响，全耦合地球系统模型（GFDL的ESM 4和NCAR的CESM 2）将以粗略分辨率运行100年。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。