Novel temperature-chain drifter for enhanced upper-ocean temperature observation

This study introduces a novel temperature-chain drifter designed to address observational gaps in upper-ocean thermal monitoring. The system combines a self-stabilizing buoy with meteorological sensors, a sea surface conductivity-temperature-depth (CTD) instrument, and a Kevlar-reinforced coaxial temperature chain capable of high-resolution vertical profiling (0–300 m). Real-time positioning and data transmission are achieved via BeiDou/Iridium satellite telemetry, while a solar-energy module ensures uninterrupted operation during observation period. This drifter was tested in a 30-day field deployment in the northern South China Sea with 20-minute sampling intervals and 80 % data transmission success. The results indicate that the drifter’s motion is driven by mesoscale eddy advection, inertial oscillations, tidal forcing, and internal waves. Temperature spectra from the drifter indicate the upper-ocean temperature is modulated by diurnal cooling, tides and internal waves. The advancements of this temperature-chain drifter establish a new paradigm for multi-parameter observation platforms, and it is particularly valuable for capturing dynamic processes in the upper ocean and air-sea interactions, especially during extreme weather events.