Fast and Slow Responses of Atlantic Meridional Overturning Circulation to Antarctic Meltwater Forcing

• Published in: Geophysical Research Letters
• Main Authors: Yechul Shin, Xin Geng, Ji‐Hoon Oh, Kyung‐Min Noh, Emilia Kyung Jin, Jong‐Seong Kug
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2024
• Subjects: Antarctic meltwater; AMOC; climate change; Geophysics. Cosmic physics; QC801-809; Antarctic; The Antarctic; Antarc*; North Atlantic
• Online Access: https://doi.org/10.1029/2024GL108272; https://doaj.org/article/3f9a1a989fec40a1ad1f6005f08f3e4f

Abstract Antarctic meltwater discharge has been largely emphasized for its potential role in climate change mitigation, not only by reducing global warming, but also by stabilizing the Atlantic Meridional Overturning Circulation (AMOC). Despite the tremendous impact of the AMOC on the climate system, its temporal evolution in response to the meltwater remains poorly understood. Here, we investigate the meltwater impacts on the AMOC based on the GFDL CM2.1 experiments and discover its fast weakening and slow strengthening to the Antarctic meltwater discharge. Cold ocean surface caused by meltwater spread throughout the globe and eventually strengthened the AMOC. However, in the early stages, the tropical temperature response could stimulate the Rossby wave teleconnection, modulating atmospheric circulation in the North Atlantic, and weakening convection and even the AMOC. This counterintuitive evolution implies a potential destabilizing effect of Antarctic meltwater, underscoring the importance of the atmospheric dynamics in the interaction between the two poles.