据介绍，全球经向翻转环流(GMOC)对于热量的重新分配很重要，也决定了全球气候，但究竟是什么决定了它在地球历史上的强度，目前还不清楚。
本研究基于两组以稳定的GMOC方向为特征的古生代气候模拟，揭示了GMOC强度主要取决于大陆构造，气候变化的影响较小。在中高纬度地区，大陆的体积在很大程度上决定了西风的速度，而西风反过来又控制了上升流和GMOC的强度。
在低纬度地区，开阔的海上航道对GMOC的强度也起着重要作用。一个半球开阔的海道允许更强的向西洋流，这使得这个半球的海面高度(SSH)比另一个半球高。经向SSH梯度驱动上层海洋跨赤道气流增强，导致GMOC增强。后者的发现丰富了当前的GMOC理论。
附：英文原文
Title: Controlling factors for the global meridional overturning circulation: A lesson from the Paleozoic
Author: Shuai Yuan, Yonggang Liu, Yongyun Hu, Jie Mei, Jing Han, Xiujuan Bao, Xiang Li, Qifan Lin, Mengyu Wei, Zhibo Li, Zihan Yin, Kai Man, Jiaqi Guo, Yue Liu, Yudong Sun, Jiacheng Wu, Jian Zhang, Qiang Wei, Jun Yang, Ji Nie
Issue&Volume: 2024-06-28
Abstract: The global meridional overturning circulation (GMOC) is important for redistributing heat and, thus, determining global climate, but what determines its strength over Earth’s history remains unclear. On the basis of two sets of climate simulations for the Paleozoic characterized by a stable GMOC direction, our research reveals that GMOC strength primarily depends on continental configuration while climate variations have a minor impact. In the mid- to high latitudes, the volume of continents largely dictates the speed of westerly winds, which in turn controls upwelling and the strength of the GMOC. At low latitudes, open seaways also play an important role in the strength of the GMOC. An open seaway in one hemisphere allows stronger westward ocean currents, which support higher sea surface heights (SSH) in this hemisphere than that in the other. The meridional SSH gradient drives a stronger cross-equatorial flow in the upper ocean, resulting in a stronger GMOC. This latter finding enriches the current theory for GMOC.
DOI: adm7813
Source: https://www.science.org/doi/10.1126/sciadv.adm7813