Prediction of Drifter Trajectory Using Evolutionary Computation

摘要

We used evolutionary computation to predict the trajectory of surface drifters.Thedata used to create the predictivemodel comprise the hourly position of the drifters, the flow and wind velocity at the location, and the location predicted by the MOHID model. In contrast to existing numericalmodels that use the Lagrangianmethod, we used an optimization algorithm to predict the trajectory. As the evaluation measure, a method that gives a better score as theMean Absolute Error (MAE) when the difference between the predicted position in time and the actual position is lower and theNormalized Cumulative Lagrangian Separation (NCLS), which is widely used as a trajectory evaluationmethod of drifters, were used.Theevolutionary methods Differential Evolution (DE), Particle Swarm Optimization (PSO), Covariance Matrix Adaptation Evolution Strategy (CMA-ES), and ensembles of the above were used, with the DE&PSO ensemble found to be the best prediction model. Considering our objective to find a parameter that minimizes the fitness function to identify the average of the difference between the predictive change and the actual change, thismodel yielded better results than the existing numerical model in three of the four cases used for the test data, at an average of 19.36% for MAE and 5.96% for NCLS.Thus, the model using the fitness function set in this study showed improved results in NCLS and thus shows that NCLS can be used sufficiently in the evaluation system.