A High-Resolution Temperature-Salinity Dataset Observed by Autonomous Underwater Vehicles for the Evolution of Mesoscale Eddies and Associated Submesoscale Processes in South China Sea

Marginal seas are usually filled with strongly varying mesoscale eddies (MEs), which evolutions plays vital roles in regulating global oceanic energy equilibrium, triggering submesoscale 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 autonomous underwater vehicles (AUVs) and gliders (UGs) actively observe oceanic motion, and could provide us spatiotemporal synchronization information for strongly varying MEs. Here, we present a 9-year high-resolution dataset of AUVs/UGs observations in 2014-2022 in the South China Sea (SCS) that can be downloaded from https://doi.org/10.57760/sciencedb.11996 (Qiu et al., 2024b). In total, 11 cruise experiments were conducted, deploying 50 UGs and 2 AUVs with spatial and temporal resolutions of <7 km and <6 hours. 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 data 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.