近日，英国伦敦大学学院Jack H. Wharton团队揭示了相对温暖的深水形成在末次盛冰期持续存在。2026年1月21日，《自然》杂志发表了这一成果。

末次盛冰期（距今1.9万至2.3万年）以温室气体浓度较低、北美及欧洲大部被大陆冰盖覆盖为特征。当时全球平均气温更低，赤道至极地的温度梯度增大，可能导致西风带增强，使得冰期气候格局与现今截然不同。然而，在此类冰川气候强迫作用下，北大西洋深海的海洋状态仍存在不确定性，这尤其归因于深海温度与盐度限定条件的稀缺。

研究组显示，冰期西北大西洋深部（>1.5公里）温度约在0–2°C之间（仅比现今低1.8±0.5°C，误差范围为2倍标准误差），在考虑全海洋变化后，海水δ¹⁸O值高出0.3±0.1‰（2倍标准误差），并可通过副极地东北大西洋和北欧海域追溯至副热带表层海水。综合水文数据，研究组揭示了西北大西洋深部的热力学结构与同位素特征，表明末次盛冰期期间西北大西洋持续生成相对温暖且可能含盐量较高的深层水。此外，该研究为用于预测未来气候变化的地球系统模型提供了更新的基准测试限定条件。

附：英文原文

Title: Relatively warm deep-water formation persisted in the Last Glacial Maximum

Author: Wharton, Jack H., Kozikowska, Emilia, Keigwin, Lloyd D., Marchitto, Thomas M., Maslin, Mark A., Ziegler, Martin, Thornalley, David J. R.

Issue&Volume: 2026-01-21

Abstract: The Last Glacial Maximum (19–23thousand years ago) was characterized by low greenhouse gas concentrations and continental ice sheets that covered large parts of North America and Europe1. Glacial climate was therefore very different, with colder global mean temperatures and an increased Equator-to-pole temperature gradient, probably resulting in stronger westerlies2. However, the state of the deep North Atlantic Ocean under these glacial climate forcings remains uncertain3,4,5,6, particularly owing to the rarity of deep-ocean temperature and salinity constraints. Here we show that the temperature of the glacial deep (>1.5km) Northwest Atlantic was approximately 0–2°C (only 1.8±0.5°C (2s.e.) colder than today), and, after accounting for the whole-ocean change, seawater δ18O was 0.3±0.1‰ (2s.e.) higher and can be traced back to the surface subtropics via the subpolar Northeast Atlantic and Nordic Seas. Together, our hydrographic data reveal the thermal and isotopic structure of the deep Northwest Atlantic and suggest sustained production of relatively warm and probably salty North Atlantic Deep Water during the Last Glacial Maximum. Furthermore, our results provide updated constraints for benchmarking Earth system models used to project future climate change.

DOI: 10.1038/s41586-025-10012-2

Source: https://www.nature.com/articles/s41586-025-10012-2