澳大利亚新南威尔士大学England, Matthew H.及其研究组提出了南极融水驱动深海翻转减速和变暖的看法。相关论文于2023年3月29日发表在《自然》杂志上。
研究人员使用一个瞬态强制高分辨率的海洋-海冰耦合模型来表明，在高排量的情境下，深海变暖将在未来30年里加速。研究人员发现，南极洲附近融水的输入导致南极底层水(AABW)的收缩，打开了让问你的环极深水更容易进入大陆架的通道。南极底层水的减少导致深海海洋变暖和老化，这与最近的测量结果相一致。相比之下，预计风和热力对南极底层水的性质、年龄和体积几乎没有影响。研究结果强调了南极融水在深海翻转中的关键作用，对全球海洋生物地球化学和气候的影响可能会持续几个世纪。
据悉，深海环流是全球经向翻转环流、热量循环、碳、氧和营养物的关键组成部分。在深海中观察到的最强的历史趋势是高纬度南部的海洋变暖，但目前还不清楚是什么过程驱动了这种变暖，以及这种变暖是否与海洋翻转环流的减缓有关。此外，由于测量数据有限，并且由于耦合的气候模型在该区域变现出偏差，因此很难将变化归因于具体的驱动因素。另外，未来的变化仍不确定，最新的协调气候模型预测没有考虑动态冰盖的融化。
附：英文原文
Title: Abyssal ocean overturning slowdown and warming driven by Antarctic meltwater
Author: Li, Qian, England, Matthew H., Hogg, Andrew McC., Rintoul, Stephen R., Morrison, Adele K.
Issue&Volume: 2023-03-29
Abstract: The abyssal ocean circulation is a key component of the global meridional overturning circulation, cycling heat, carbon, oxygen and nutrients throughout the world ocean. The strongest historical trend observed in the abyssal ocean is warming at high southern latitudes, yet it is unclear what processes have driven this warming, and whether this warming is linked to a slowdown in the ocean’s overturning circulation. Furthermore, attributing change to specific drivers is difficult owing to limited measurements, and because coupled climate models exhibit biases in the region. In addition, future change remains uncertain, with the latest coordinated climate model projections not accounting for dynamic ice-sheet melt. Here we use a transient forced high-resolution coupled ocean–sea-ice model to show that under a high-emissions scenario, abyssal warming is set to accelerate over the next 30years. We find that meltwater input around Antarctica drives a contraction of Antarctic Bottom Water (AABW), opening a pathway that allows warm Circumpolar Deep Water greater access to the continental shelf. The reduction in AABW formation results in warming and ageing of the abyssal ocean, consistent with recent measurements. In contrast, projected wind and thermal forcing has little impact on the properties, age and volume of AABW. These results highlight the critical importance of Antarctic meltwater in setting the abyssal ocean overturning, with implications for global ocean biogeochemistry and climate that could last for centuries.
DOI: 10.1038/s41586-023-05762-w
