The research team led by Academician Wu Lixin from the Frontier Science Center for Deep Ocean Multispheres and Earth System/Key Laboratory of Physical Oceanography, has made significant progress in the research field of subtropical western boundary currents (WBCs). Their research revealed that subtropical WBCs are intensifying onshore in a warming climate, and further illustrated the underlying dynamic mechanism. The findings were reported online in Nature Climate Change titled Onshore intensification of subtropical western boundary currents in a warming climate. 

Subtropical WBCs are among the strongest ocean currents globally. They play a crucial role in the transport of oceanic mass and energy, and significantly influence coastal dynamics and ecosystems. Accurate assessment of changes in subtropical WBCs is therefore vital for global climate prediction and coastal environmental assessment. By analyzing data from high-resolution coupled atmosphere-ocean models, the team discovered that subtropical WBCs intensify significantly on their onshore side as global warming intensifies. The onshore acceleration ranges from 0.10 ± 0.08 to 0.51 ± 0.24 cm/s² per decade. Further study figured out a strong correlation between the onshore intensification of subtropical WBCs and changes in ocean stratification. By developing a dynamic model for the vertical scale of WBCs, the research revealed a dynamic link between the vertical scale of the WBC and ocean stratification. Their findings suggest that as ocean stratification intensifies, the vertical scale of subtropical WBCs will gradually decrease and shift upwards, resulting in an intensification of the current on its shoreward side.

The study indicated that the onshore intensification of subtropical western boundary currents (WBCs) will accelerate warming in marginal seas and shelf seas. Consequently, this will lead to stronger and more frequent marine heatwaves, reduce the capacity of adjacent seas to absorb carbon dioxide, and potentially destabilize seafloor methane hydrates in shelf regions. Therefore, it is crucial to establish a more comprehensive observation system in WBC regions to conduct long-term, continuous monitoring of the onshore migration of WBCs and their associated impacts. This research stands as the first to systematically reveal the characteristics and controlling mechanisms of the onshore migration of subtropical WBCs under global warming. It is of great significance for advancing our understanding of how the western boundary current system responds to climate change.