Atmospheric Synoptic Variability and Pacific Ocean Biogeochemistry in the Current and Future Climate (SyVarBio)

当前和未来气候中的大气天气变化和太平洋生物地球化学（SyVarBio）

• 批准号: 434479332
• 负责人: Dr. Olaf Duteil
• 金额: --
• 依托单位: Arbeitsgruppe Paläoklimamodellierung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/434479332?language=en
• 关键词: Atmospheric; Synoptic; Variability; Pacific; Ocean

Projections based on Earth system models (ESMs) suggest that the ocean environment will dramatically change in the next 100 years should global surface warming continue at the present rate. A future expansion of the tropical “Oxygen Minimum Zones” (OMZs) associated with changes of the functioning of the Eastern Boundary Upwelling Systems (EBUSs) will have major regional and global consequences for the marine ecosystems and the climate. One of the main mechanisms controlling the oxygen levels and the upwelling productivity is the wind-driven ocean circulation. The water transport and the surface buoyancy fluxes depend not only on the intensity of the time-averaged winds but also on the magnitude of the high-frequency Atmospheric Synoptic Variability (ASV), in particular related to extreme events such as tropical cyclones, storms, strong convective patterns. While both time-averaged and high-frequency components will change in a future climate, the specific impacts of a change in ASV are currently overlooked. The objectives of SyVarBio are to: i) understand the relative roles of changes in ASV and time-averaged winds in impacting marine biogeochemical cycles and OMZs by performing dedicated sensitivity experiments with a state-of-art coupled atmosphere – ocean – biogeochemical modeling framework. Large-scale and mesoscale experiments will be performed using the Nucleus for European Modeling of the Ocean (NEMO) framework and will make use of previously simulated fields by the Kiel Climate Model System. A regional focus will be given to the Costa Rica thermal dome in the Eastern Tropical North Pacific, a biodiversity hotspot located close to the Intertropical Convergence Zone and in the most extended OMZ of the world; ii) investigate whether the ASV is realistically represented in a suite of ESMs and to which extent future changes in oxygen levels and productivity are related to changes in ASV. A subsample of simulations performed in the context of the Coupled Model Intercomparison Project phase 6 (CMIP6) will be analyzed using statistical tools and machine learning techniques. By combining these two objectives, involving a process study complemented by an intercomparison analysis of an existing model database, the project SyVarBio will help filing in a knowledge gap regarding the importance of the ASV in the modulation of the Pacific Ocean tropical and subtropical circulation and biogeochemical cycles in the current and future climate.

根据地球系统模型（ESM）的预测表明，如果全球表面变暖继续以目前的速度发展，海洋环境将在未来100年内发生巨大变化。与东部边界上升流系统功能变化有关的热带“最低含氧量区”的未来扩大将对海洋生态系统和气候产生重大的区域和全球影响。风驱动的海洋环流是控制氧气水平和上升流生产力的主要机制之一。水的输送和表面浮力通量不仅取决于时间平均风的强度，而且还取决于高频大气天气变率（ASV）的大小，特别是与极端事件，如热带气旋，风暴，强对流模式。虽然时间平均和高频分量都将在未来气候中发生变化，但ASV变化的具体影响目前被忽视。SyVarBio的目标是：i）通过使用最先进的耦合大气-海洋-地球化学建模框架进行专门的敏感性实验，了解ASV和时间平均风变化在影响海洋地球化学循环和OMZ方面的相对作用。将利用欧洲海洋模拟核心框架进行大尺度和中尺度实验，并将利用以前由基尔气候模型系统模拟的场。一个区域的重点将给予哥斯达黎加热圆顶在热带北太平洋东部，生物多样性热点位于靠近热带辐合带，并在世界上最广泛的OMZ; ii）调查是否ASV是现实的代表在一套ESM和在何种程度上氧气水平和生产力的未来变化有关的变化ASV。将使用统计工具和机器学习技术分析在耦合模型相互比较项目第6阶段（CMIP 6）背景下进行的模拟子样本。通过将这两个目标结合起来，包括一项过程研究，并辅之以对现有模型数据库的相互比较分析，SyVarBio项目将有助于填补关于ASV在调节太平洋热带和亚热带环流以及当前和未来气候中的地球化学循环方面的重要性的知识空白。