Investigating the impact of physical processes in the Southern Ocean on the carbon cycle during past, present and future climates

研究过去、现在和未来气候下南大洋物理过程对碳循环的影响

• 批准号: 75465893
• 负责人: Dr. Peter Köhler
• 金额: --
• 依托单位: Alfred-Wegener-Institut (AWI) Helmholtz-Zentrum für Polar- und Meeresforschung
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/75465893?language=en
• 关键词: Investigating; impact; physical; processes; Southern

The importance of the Southern Ocean for the global carbon cycle and atmospheric CO2 has been demonstrated by various recent data- and model-based studies. This includes present and potential future CO2 uptake, as well as the reduction in atmospheric pCO2 during the Last Glacial Maximum. Especially for the latter, various different mechanisms in the Southern Ocean have been proposed to explain some of the changes in pCO2, which are observed in ice cores, while a more convincing study which brings hypotheses into context with our physical knowledge based on ocean models and paleo reconstructions remains elusive so far. In this project we will explore the physical basis of various of these hypothesis on the (partial) explanation of glacial pCO2 values with a well established ocean general circulation model (MITgcm). We will analyse (a) if and how temporal and spatial changes in the wind field over the Southern Ocean lead to variations in water column stratification; (b) the impact of changing sea ice coverage (based on paleo-reconstructions or future predictions) on water properties and thus on stratification and ocean circulation; (c) interacting effects of both changes in wind and sea ice on Southern Ocean physics. Besides a physical understanding of these processes their impact on the Southern Ocean CO2 sink capacities, the global carbon cycle and on atmospheric pCO2 will be in focus. These topics are explored under preindustrial, present-day and glacial boundary conditions, but also for selected IPCC scenarios of future climate change.

南大洋对全球碳循环和大气CO2的重要性已由最近各种基于数据和模型的研究所证明。这包括当前和未来可能的二氧化碳吸收，以及末次冰盛期大气pCO 2的减少。特别是对于后者，已经提出了南大洋的各种不同机制来解释在冰芯中观察到的pCO 2的一些变化，而更有说服力的研究将假设与我们基于海洋模型和古重建的物理知识结合起来，迄今为止仍然难以捉摸。在这个项目中，我们将探索各种这些假设的物理基础上（部分）解释冰川pCO 2值与一个完善的海洋环流模式（MITgcm）。我们将分析（a）南大洋风场的时空变化是否以及如何导致水柱分层的变化;（B）海冰覆盖率变化（根据古重建或未来预测）对水的性质的影响，从而对分层和海洋环流的影响;（c）风和海冰变化对南大洋物理的相互影响。除了对这些过程的物理理解外，它们对南大洋CO2汇能力、全球碳循环和大气pCO 2的影响也将是重点。这些主题是在工业化前，当今和冰川边界条件下探讨的，但也为选定的IPCC未来气候变化情景。