Detection of drogue loss events from drifter positioning data

IV Encuentro Oceanografía Física Española, celebrado del 20 al 22 de julio de 2016 en Alicante, España.-- 3 pages, 1 figure

Satellite-tracked drifting buoys are useful for sampling sea-surface currents. Standard drifting buoys have drogues centred at a depth of 15 m, a fundamental element that guarantees that the direct wind force on the buoy is much smaller than the drag on the anchor. When a drifter loses its drogue, it no longer becomes a good tracker of the surface currents, hence the relevance of identifying when this happens. Here we propose a spectral-based approach to analyse drifter velocity data so as to detect when a drifter loses its drogue without the need of concurrent wind data. The method, applied to data obtained during the SPURS 2013 cruise, shows a substantial increase in the band-passed velocity energy at the time the drifter loses its drogue, as deduced with an independent method that considers the temporal change of the correlation between wind and positioning data. The results are very promising, pointing at a new method that can detect drogue loss from a relatively simple analysis of positioning data

This research has been supported by the Ministerio de Economía y Competitividad of the Spanish Government through project VA-DE-RETRO (CTM2014-56987-P). Ignasi Vallès has been funded through a FPI contract of the Ministerio de Competitividad y Economía. The drifter data was obtained following deployments during the SPURS cruise, in the frame of the MIDAS-6 (AYA2010-22062-C05-01) project, financed by the Ministerio de Economía y Competitividad of the Spanish Government

Peer Reviewed