加强东北大西洋氧气最小区的通风,缓解南部翻转的降冰速度
Sofía Barragán-Montilla1,2, Heather J H Johnstone3, Stefan Mulitza3,4
1MARUM-Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany. sbarraganmontilla@marum-alumni.de.
Nature communications
|July 15, 2025
概括
东部热带北大西洋氧气最小区 (ETNA OMZ) 在冰川时期经历了更高的氧气水平. 这是由于加剧的地下海洋循环与较弱的大西洋南部翻转循环 (AMOC) 相关.
科学领域:
- 古海洋学是古海洋学.
- 海洋生物地质化学海洋生物地质化学
- 气候动力学 气候动力学
背景情况:
- 东部热带北大西洋氧气最小区 (ETNA OMZ) 对海洋生态系统至关重要.
- 大西洋亚热带旋转的地下海洋循环通风了ETNA OMZ.
- 浅水循环和大西洋南部翻转循环 (AMOC) 强度之间的相互作用是不太了解的.
研究的目的:
- 为了研究AMOC强度和ETNA OMZ氧化之间的关系.
- 为了重建ETNA OMZ边缘的高分辨率古氧化变化.
- 了解控制这一关键海洋地区氧气水平的机制.
主要方法:
- 使用结合底部和孔隙水分析生成了高分辨率的古氧化记录.
- 从ETNA OMZ边缘 (793米水深) 分析的沉积物核心GeoB9512-5.
- 与古气候事件相关的氧化变化,如最后的冰川最大值 (LGM),海因里希斯塔迪亚尔1 (HS1) 和年轻的干旱 (YD).
主要成果:
- 在LGM,HS1和YD期间,ETNA OMZ边际呈现出更高的氧化.
- 在HS1和YD期间更的午线温度梯度与AMOC减速相吻合.
- 这些条件加剧了地下亚热带细胞循环,增加了ETNA OMZ的氧气供应.
结论:
- AMOC的减速严重影响了ETNA OMZ的通风.
- 在AMOC减弱期间,加剧的地下循环增加了氧气供应.
- 这项研究阐明了大规模海洋循环与区域氧气最小区动态之间的联系.
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