Sedimentation dynamics and microbial degradation of marine aggregates: hydrodynamic fundamentals of particulate carbon transport in the ocean

海洋聚集体的沉积动力学和微生物降解：海洋中颗粒碳传输的水动力基础

• 批准号: 276129098
• 负责人: Professor Dr. Hans-Peter Grossart, since 12/2016
• 金额: --
• 依托单位: Department of Computer Science and Electrical Engineering
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/276129098?language=en
• 关键词: Sedimentation; dynamics; microbial; degradation; marine

Marine aggregates build the backbone of biological carbon pump in the ocean by exporting the particulate organic carbon into the deeper water layers via sedimentation.We target at constructing a combined hydrodynamic-microbiological project for characterization of effective vertical transport by marine aggregates with special emphasis on microbial turnover rates within the aggregates. By combining the laboratory experiments with numerical simulations, we first parametrize the sinking velocity of the aggregates as a function of size, porosity, composition and density stratification of the ambient fluid. Next, the mass transfer between the interstitial fluid and the ambient water as well as the microbial turnover rates within the aggregates will be determined as a function of sinking velocity. Based on this, a mathematical model will be developed which mimics reliably the sinking velocity and mass transfer. Such a model will enable us for the first time to provide a realistic estimation of the efficiency of the biological carbon pump. Furthermore, the model delivers valuable inputs and approaches to integrate marine processes into available global climate and oceanic carbon circulation models.

海洋团聚体通过沉积物将颗粒有机碳输出到更深的水层，从而构成海洋中生物碳泵的支柱。我们的目标是构建一个水动力-微生物相结合的项目，以表征海洋团聚体的有效垂直运输，并特别强调团聚体内的微生物周转率。通过实验室实验和数值模拟相结合，我们首先将聚集体的下沉速度参数化为环境流体的大小、孔隙度、组成和密度分层的函数。接下来，将确定间质流体和环境水之间的传质以及聚集体内的微生物周转率作为下沉速度的函数。在此基础上，建立了可靠模拟下沉速度和传质过程的数学模型。这样的模型将使我们第一次能够对生物碳泵的效率提供现实的估计。此外，该模式提供了有价值的投入和方法，将海洋过程纳入现有的全球气候和海洋碳循环模式。