The progressive wind vector for the above dates, obtained from the Gascony station data, is shown in Fig. 2.
There is a similarity between the buoy drift (Fig. 1) and the progressive wind vector, even when the buoy position was located significantly far away from the Gascony station. This drifting pattern is characteristic of winters, in the Bay of Biscay, where the depressions with southwesterly winds occur frequently near the coast of Galicia.
These are combined with northwesterly storms, caused by low pressure systems located to the west of the British Isles. The influence of the former extends up to the eastern part of the Bay of Biscay, whilst the latter reaches the Cantabrian coast.
Following this comparison, wind appears to be a basic mechanism affecting oil dispersion processes.