Abstract:
The ocean’s dynamic response to anthropogenic warming spans scales from local fronts to global overturning. This presentation synthesizes multi-decadal observations, reanalysis, and model simulations to trace these interconnected changes. At the mesoscale, we reveal a systematic shoreward migration of eddy kinetic energy and sea surface temperature gradients, driven by intensified near-coast winds and enhanced ocean stratification. This redistribution alters coastal heat, nutrient, and carbon exchange. Progressing to basin scales, we uncover a unifying mechanism for the complex zonal shifts of subtropical western boundary currents: a competition between wind stress curl and stratification, whose regional balance explains observed heterogeneity. At the climate scale, we demonstrate active cryosphere-ocean feedback, where Arctic Sea ice loss triggers an atmospheric response that directly impacts the upper branch of the Atlantic Meridional Overturning Circulation (AMOC) and Atlantic meridional heat transport. Finally, we establish subpolar North Atlantic sea surface salinity as a robust, process-based indicator of the AMOC’s mean state, offering a critical lens for assessing its stability. Together, these findings contribute to a more integrated view of ocean dynamical responses across meso- to large scales under global warming.

Biography:
Dr. Fanghua Xu is an Associate Professor in the Department of Earth System Science at Tsinghua University. Her research focuses on large-scale ocean dynamics, mesoscale eddy processes, air-sea interaction, and the stability of the Atlantic overturning circulation. She earned her Ph.D. from Stony Brook University and was a postdoctoral scholar at Princeton University. Dr. Xu has published more than 60 papers in peer-reviewed journals. She serves as a member of the steering committee of the International Workshop on Modeling the Ocean (IWMO), and also contributes to the scientific community as an Editor for the Journal of Geophysical Research: Oceans and an Associate Editor for Ocean Dynamics.