The role of bottom boundary turbulence for the transport of tracers in marine basins (ROBOTRACE)

底部边界湍流对于海洋盆地示踪剂传输的作用 (ROBOTRACE)

• 批准号: 322366882
• 负责人: Dr. Peter Holtermann
• 金额: --
• 依托单位: Sektion Physikalische Ozeanographie und Messtechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/322366882?language=en
• 关键词: role; bottom; boundary; turbulence; transport

The main objective of this proposal is to identify, analyse, and quantify the physical processes contributing to the exchange of dissolved substances between the sediment-water interface, the turbulent BBL (bottom boundary layer), and the weakly turbulent interior of stratified basins. The focus will be on the effect of sloping topography, where the exchange is complicated by the interplay between BBL restratification, BBL turbulence, and sub-mesoscale processes that are assumed to determine the lateral exchange of fluid between the BBL and the interior. These processes will be investigated here with a combined experimental and numerical modelling approach. More specifically, the project will focus on the sediment-water exchange processes of oxygen and sulphide, which will be measured in situ by an eddy-correlation and a microprofiling system. These measurements will be accompanied by a set of standard oceanographic instrumentation as well as ship- and mooring-based turbulent measurements, creating a novel dataset of (A) sediment-water fluxes of oxygen/sulphide with (B) turbulence measurements within the BBL and the interior water column. In addition to the in situ measurements a numerical investigation will be based on an implementation of a simplified sediment model in combination with a parameterisation of the transport processes across the sediment-water interface. This model will be used in idealised one-dimensional parameter studies as well as in a two-dimensional BBL exchange setup at a sloping topography. Also a fully three-dimensional realistic model of the central Baltic Sea will be setup and used to investigate the role of three-dimensional features as eddies on the transport of oxygen/sulphide.

这一建议的主要目标是确定、分析和量化有助于层状盆地的沉积物-水界面、湍流BBL(底边界层)和弱湍流内部之间的溶解物质交换的物理过程。重点将放在倾斜地形的影响上，那里的交换因边界层再层化、边界层湍流和次中尺度过程之间的相互作用而变得复杂，这些过程被认为决定了边界层和内部之间的横向流体交换。这些过程将在这里用实验和数值模拟相结合的方法进行研究。更具体地说，该项目将侧重于氧和硫化物的沉积物-水交换过程，这将通过涡旋相关和微轮廓系统进行现场测量。这些测量将伴随着一套标准的海洋仪器以及基于船舶和系泊的湍流测量，从而创建一个新的数据集，其中包括(A)氧/硫化物的沉积物-水通量，以及(B)海底边界层和内部水柱内的湍流测量。除了现场测量外，还将在实施简化沉积物模型的基础上进行数值调查，并结合沉积物-水界面的输送过程的参数。该模型将用于理想化的一维参数研究以及在倾斜地形的二维边界层交换装置中。此外，还将建立一个波罗的海中部的全三维真实模型，并用于研究涡流等三维特征在氧/硫化物输送中的作用。