The Antarctic Intermediate Water (AAIW) is an essential global ocean water mass at intermediate depths. Coupled climate models in isotope-enabled (δ¹⁸O, δD), fully coupled Community Earth System Model and Paleoclimate Model Intercomparison Project Phase 3 consistently show shallower AAIW depth at the Last Glacial Maximum (LGM) due to the northward shift of AAIW. More importantly, modeling results suggest that the northward shift of AAIW can be caused by sea ice expansion and the weakened hydrological cycle under the glacial climate. On the contrary, the AAIW under global warming tends to shift poleward compared to the pre-industrial period driven by the retreating sea ice and strengthened hydrological cycle. However, the AAIW depth will shallow in response to the ongoing warming, likely due to the overwhelming effects of enhanced stratification and shallowing mixed layer.

中文翻译：

---

通过海冰和水文循环的变化使南极冰川中层水变浅

南极中层水 (AAIW) 是处于中等深度的重要全球海洋水团。启用同位素的耦合气候模型 ( δ ¹⁸ O, δD)，由于 AAIW 向北移动，完全耦合的社区地球系统模型和古气候模型比对项目第 3 阶段始终显示末次盛冰期 (LGM) 较浅的 AAIW 深度。更重要的是，建模结果表明，AAIW 的北移可能是由于冰川气候下海冰扩张和水文循环减弱所致。相反，在海冰退缩和水文循环加强的驱动下，与工业化前时期相比，全球变暖下的 AAIW 趋向于向两极转移。然而，AAIW 深度会随着持续变暖而变浅，这可能是由于分层增强和混合层变浅的压倒性影响。