The model of tracing drift targets and its application in the South China Sea

A Leeway-Trace model was established for the traceability analysis of drifting objects at sea. The model was based on the Leeway model which is a Monte Carlo-based ensemble trajectory model, and a method of realistic traceability analysis was proposed in this study by using virtual spatiotemporal drift trajectory prediction. Here, measured data from a drifting buoy observation experiment in the northern South China Sea in April 2019, combined with surface current data obtained from the finite volume community ocean model (FVCOM), were used for the traceability analysis of humanoid buoys. The results were basically consistent with the observations, and the assimilation of measured current data can significantly improve the accuracy of the traceability analysis. Several sensitive experiments were designed to discuss the effects of wind and tide on the traceability analysis, and their results showed that the wind-driven current and the wind-induced leeway drift are both important to the traceability analysis. The effect of tidal currents on traceability could not be ignored even though they were much weaker than the residual currents in the experimental area of the northern South China Sea.