Trends in water mass properties in the Weddell Sea from assimilation of float data in a regional ocean model

通过区域海洋模型中浮标数据的同化，得出威德尔海水团特性的趋势

• 批准号: 75404546
• 负责人: Dr. Martin Losch, Ph.D.
• 金额: --
• 依托单位: Sektion Klimadynamik
• 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 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/75404546?language=en
• 关键词: Trends; water; mass; properties; Weddell

Climate change is strongly conditioned by variations in key areas of the ocean. The Weddell Sea is such a key area, where a major amount of Antarctic Bottom Water (AABW) is formed as an essential contribution to the Meridional Overturning Circulation (MOC). Up to now, hydrographic observations were strongly biased in time toward summer season and spatially toward two repeated WOCE-sections. Within this project all available observational data will be combined with a numerical ocean model with the help of dynamical consistent data assimilation into a complete stateestimate of the Weddell Sea. The main emphasis is placed on collecting and using temperature- and salinity profiles of newly developed ice compatible Argo floats which remove the aforementioned biases. The resulting estimate and the complete phase-space trajectory of the Weddell Sea will enable us to answer the following questions: • How do water mass properties change in the Weddell Gyre, in particular to what extent are the sparse hydrographic observations characteristic for the entire Weddell Sea? • What causes the changes in water mass properties within the Weddell Sea? • To what extent are water mass properties and inflow of Circumpolar Deep Water (CDW) subject of short- and intermediate term variations? Is it possible to detect long-term trends? • How do variations in the WDW-range affect deep and bottom water formation within the Weddell Sea? Further, this work will provide a dynamically consistent time series of the water mass properties of the Weddell Gyre and will be an essential contribution to the project bundle “The role of the Atlantic sector of the Southern Ocean in the climate system”.

气候变化在很大程度上取决于海洋关键区域的变化。威德尔海是这样一个关键区域，在那里形成了大量的南极底层水（AABW），作为经向翻转环流（MOC）的重要贡献。到目前为止，水文观测强烈偏向于在时间上对夏季和空间上对两个重复的WOCE部分。在这个项目中，所有现有的观测数据将与数值海洋模型相结合，并借助动力学一致性数据同化，形成威德尔海的完整状态估计。主要重点放在收集和使用新开发的冰兼容阿尔戈浮标的温度和盐度剖面，消除了上述偏见。由此产生的估计和完整的相空间轨迹的威德尔海将使我们能够回答以下问题：·水的质量属性如何在威德尔环流的变化，特别是在何种程度上是稀疏的水文观测特性为整个威德尔海？·是什么导致威德尔海水体性质的变化？·在何种程度上，水团特性和绕极深水（CDW）的流入量受短期和中期变化的影响？是否有可能发现长期趋势？·WDW范围的变化如何影响威德尔海的深水和底层水的形成？此外，这项工作将提供威德尔环流水团特性的动态一致时间序列，并将对“南大洋大西洋部分在气候系统中的作用”项目包作出重要贡献。