Persistent Modulation of AMOC Multidecadal Variability on Tropical North Atlantic Subsurface Temperature Under Global Warming in the CESM1‐LE

Abstract Previous studies emphasized a significant linkage between Atlantic Meridional Overturning Circulation multidecadal variability (AMOC‐MV) and subsurface temperature in the Tropical North Atlantic (TNA). However, as AMOC‐MV weakens under global warming, it remains unclear whether this linkage persists. Here, we use the Community Earth System Model version 1 Large Ensemble to demonstrate that the connection remains robust under global warming. We highlight that the TNA subsurface response and its changes are primarily confined to the western boundary, regulated by variations in the AMOC‐MV‐related North Brazil Current. In the TNA western boundary, a subsurface temperature dome, which dominates the subsurface thermal response by strengthening meridional heat transport, shifts southward due to changes in mean‐state AMOC and local winds. This southward shift extends the subsurface temperature response equatorward, amplifying the mean TNA response. The sustained linkage supports using TNA subsurface temperature as an indicator for future AMOC‐MV monitoring.