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How the ocean circulation changes in a warming climate is an important but poorly understood problem. Using a global ocean model, we decompose the problem into distinct responses to changes in sea surface temperature, salinity, and wind. Our results show that the surface warming effect, a robust feature of anthropogenic climate change, dominates and accelerates the upper ocean currents in 77% of the global ocean. Specifically, the increased vertical stratification intensifies the upper subtropical gyres and equatorial currents by shoaling these systems, while the differential warming between the Southern Ocean upwelling zone and the region to the north accelerates surface zonal currents in the Southern Ocean. In comparison, the wind stress and surface salinity changes affect regional current systems. Our study points a way forward for investigating ocean circulation change and evaluating the uncertainty.

Marginal seas are usually fulfilled with strongly varying mesoscale eddies (MEs), which evolutions plays vital roles in regulating global oceanic energy equilibrium, triggering subemesoscale processes with strong vertical velocity, and inducing high biogeochemistry transport. But the temporal evolutions of MEs and submesoscale processes with several kilometers' resolutions are difficult to be measured by traditional observations with passive working mode. The automatic underwater gliders (AUGs) and vehicles (AUVs) positively observe oceanic motion, and could provide us spatiotemporal synchronization information for strongly varying MEs. Here, we present a 9-year high dense dataset of AUVs/AUGs observations in 2014–2022 in the South China Sea (SCS) can be downloaded from https://doi.org/10.57760/sciencedb.11996 (Qiu et al., 2024b). Totally, 9 AUG and 2 AUV cruise experiments were conducted, and 83 AUGs (2 AUVs) equipment were deployed with zonal and temporal resolutions of < 7 km and <6 hour. It covers the area of eddy's birth, propagation, and dissipation, presenting us the most complete data to investigate the evolution of MEs at different life stages. 40 % of them reach resolutions < 1 km and < 1 hour, which provides us the dynamic characteristics of submesoscale instabilities across and along front at the eddy edge. This dataset has potential in improving the forecast accuracy in physical and biogeochemistry numerical model. Much more aggressive field investigation programs will be promoted by the NSFC in future. [ABSTRACT FROM AUTHOR]