Cruise and glider observations in the Northern South China Sea (May–June 2021).

The observations were conducted across an anticyclonic eddy to characterize its physical and biogeochemical characteristics.The shipboard observations consist of vertical profiles of temperature, salinity, ocean currents, chlorophyll-a, and nutrient concentrations. An autonomous underwater glider (reference number: 1000K012) was deployed concurrently to obtain repeated vertical profiles from the surface to 1000 m depth.

The glider measured temperature, salinity, chlorophyll-a, and turbidity. This dataset provides high-resolution observations of the eddy structure and associated biophysical properties, which can be used for studies of mesoscale ocean dynamics, eddy impacts on biological distributions, and model validation.