Collaborative Research: Towards an Understanding of the Role of the Atlantic Theremohaline and Wind Driven Circuluation in Tropical Atlantic Variability (TAV)

最近的耦合气候模式模拟表明，大西洋温盐环流的变化可以引起热带大西洋耦合气候系统的实质性响应，进而对全球气候产生影响。如果这被证明是正确的，这些模拟结果将对我们对海洋在全球气候变化中的作用的理解产生巨大的影响。因此，对我们来说，全面了解高纬度地区和热带地区变化之间的动力学过程是至关重要的。这个项目的重点是海洋联系。特别是，研究人员将探讨大西洋经向翻转槽（MOC）的变化如何影响副热带槽（STCs）的路径，以及这些副热带槽的变化如何影响海表温度（SSTs），以及这些海表温度的变化如何影响热带大西洋的耦合气候变率。调查将通过结合观测分析的一系列耦合气候模式来进行。一个大气模式与一个2.5层减少重力-海洋模式耦合，可能是最简单但最有效的耦合模式，适合研究MOC/STC相互作用及其对耦合气候变率的影响，将通过改变施加MOC的强度来进行广泛的面向过程的实验，以揭示MOC对热带大西洋变率（TAV）的影响。然后，将迫使一个大气环流模式与一个能够解析热带大西洋环流中尺度特征的区域高分辨率海洋环流模式耦合，穿过其南北开放边界，从而更完整地观察MOC/STCs对耦合反馈的影响。最后，将分析用于IPCC评估的综合全球耦合气候模式的输出，并将其与其他两个模式实验结合使用，以进一步了解大西洋MOC变化对全球气候的影响。学术价值：本研究的预期结果将对理解大西洋气候变率和全球气候变化的基本海洋环流物理做出重要贡献。通过对耦合模式实验的假设检验和系统检查，期望从这项研究中得出一个关于大西洋环流不同组成部分之间联系的更精确的理论。本研究开发的建模工具将对未来的气候研究有价值。更广泛的影响：拟议的研究解决了与气候变化科学辩论和讨论相关的问题。拟议的研究将加强我们对热带大西洋部门长期气候变率的理解，这对该地区各国具有重要的社会和经济影响。这项研究的结果将有助于教育公众关于海洋在全球气候变化中的重要性。该项目还将通过直接让研究生和博士后研究人员与教师一起进行研究，帮助培养下一代物理海洋学家和气候科学家。该项目的部分研究成果将纳入TAMU的研究生课程。

ABSTRACTOCE-0623345Recent coupled climate model simulations show that changes in thermohaline circulation in the Atlantic Ocean can lead to a substantial response in the tropical Atlantic coupled climate system, which in turn can have an impact on global climate. If this proves correct, these modeling results can have tremendous implications on our understanding of the role of the ocean in global climate change. For this reason, it is critically important for us to gain a comprehensive understanding of the dynamical processes that link the changes in high latitudes to those in the tropics. The focus of this project is on the oceanic linkage. In particular, the investigators will explore how changes in the Atlantic Meridional Overturning Cell (MOC) can affect the pathways of the Sub-Tropical Cells (STCs), and how these changes in the STCs can affect the Sea Surface Temperatures (SSTs), and finally how these SST changes can affect the coupled climate variability in the tropical Atlantic. The investigation will be conducted via a hierarchy of coupled climate models in conjunction with observational analysis. An atmospheric model coupled to a 2.5-layer reduced-gravity-ocean model, perhaps the simplest and yet most efficient coupled model suited to investigate MOC/STC interaction and its effect on coupled climate variability, will be used to conduct extensive process-oriented experiments by varying the strength of the imposed MOC to shed light on the effect of the MOC on the Tropical Atlantic Variability (TAV). Then , an atmospheric circulation model coupled to a regional high resolution ocean circulation model capable of resolving mesoscale features in the tropical Atlantic circulation will be forced through its northern and southern open boundaries to allow a more complete look at the effect of the MOC/STCs on coupled feedback. Finally, the output of a comprehensive global coupled climate model used for IPCC assessment will be analyzed and used in conjunction with the other two model experiments to gain further understanding of the impact of Atlantic MOC change on global climate.INTELLECTUAL MERIT: The anticipated outcome of this research will make an important contribution to the understanding of the fundamental ocean circulation physics in Atlantic climate variability and global climate change. A more refined theory of the connection between the different components of the Atlantic ocean circulation is expected to emerge from this study through hypothesis testing and systematic examination of the coupled model experiments. The modeling tools developed in this study will be valuable for future climate studies. BROADER IMPACT: The proposed research addresses the issues pertinent to debates and discussions in climate change sciences. The proposed research will enhance our understanding of long-term climate variability in the tropical Atlantic sector, which has important social and economic impacts on countries in the region. The findings from this study will help educate the general public about the importance of the oceans in global climate change. The project will also help train the next generation of physical oceanographers and climate scientists by directly involving graduate students and postdoctoral researchers in research endeavors with faculty. Some of research results from this project will be integrated into the graduate courses at TAMU.