Optimum deployment of satellite-tracked drifters to support iceberg drift forecasting: Fid-Bau Portal

Optimum deployment of satellite-tracked drifters to support iceberg drift forecasting

Venkatesh, S. / Sanderson, B. / El-Tahan, M.

AbstractThe objective of this work is to devise strategies for optimum deployment of Tiros satellite-tracked Ocean Drifters (TOD) in order to derive measurements of ocean currents for iceberg drift forecasting off the Canadian east coast. The mean velocity field and its standard deviation are determined from several data sources. The velocity field and its variability are used by a trajectory model to determine the probable movement of a TOD released in the study area.A desirability index is defined to quantify the need for TOD measuremennts at a site in terms of: the amount and type of human activity; the variability and knowledge of ocean currents; and the iceberg population density, and other considerations. This enables us to develop a method for arriving at a TOD deployment agenda.Based on data from oil drilling operations off Labrador and Newfoundland, typical residence times for TOD's is about 2.5 months. For the area off Labrador, TOD releases should be within the Labrador current (between the 200 m and 1000 m isobaths) as far north as pack ice allows. Peak release rates off Newfoundland should be in May to July in order to coincide with peak iceberg numbers.A prohibitive number (1000) of TOD's would be required to resolve eddy structure in the areas considered. However, a more reasonable number (20–100) of TOD's would adequately resolve much of the wind-induced current variability.