A tri-point correlation method for ocean current estimation and its applications in near-bottom turbulent mixing on the shelf of the Northern South China Sea.

This article presents a novel tri-point correlation method to estimate ocean currents using temperature data from three fixed sensors arranged in an equilateral triangle on the ocean floor. Applied to high-resolution temperature measurements collected at the northern South China Sea shelf bottom, the method infers current speed and direction by determining transit times between temperature signals via cross correlation, showing strong agreement with direct current meter measurements. Utilizing the inferred currents and temperature data, the study further estimates near-bottom turbulent mixing parameters—including turbulent kinetic energy dissipation rate, turbulent diffusivity, and vertical heat flux—and finds these quantities positively correlated with internal wave activity. The results demonstrate the method's effectiveness for assessing ocean interior currents and associated turbulent mixing, offering a new approach that circumvents the need for simultaneous microstructure velocity measurements.