Current data derived from ocean drifters for oil spill modelling

An interactive PC Windows program (DRIFTAP) has been developed for Environment Canada for generating surface current information using positional data from drifting buoys. The current information, in either vector field or tidal harmonic constant form, is suitable for input to oil spill models. The user interface in DRIFTAP provides extensive control over input data editing, file access, functions for the correction of position errors, track smoothing using polynomial spline-fitting, viewing selected raw and processed drift tracks, interpolation of drift track velocities onto regularly spaced grid locations, smoothing and modelling the field data and viewing or printing of non-gridded and gridded velocities. All data are gee-referenced and can be displayed under several map projections. Future improvements would include the addition of a graphical grid and mask editor and faster execution times through optimization of the grid-point smoothing filter.