When emergency intervention is requ

When emergency intervention is required
Whenever an object without an active propulsion system is lost on the sea-surface, it is subjected
to forces caused by the surrounding environment, mainly due to the effect of wind and surface
currents. Those forces cause the drift of the object that will move from the original position; the
amount of motion is called leeway (Allen and Plourde, 1999).
Such an emergency scenario can be caused by many accidents such as the fall of men, objects or
hazardous material overboard, the launch of life rafts or the loss of an airplane in the ocean. In all
these cases it is necessary to activate procedures aimed at finding the missing object or person in the
shortest possible time. To do that a precise estimation of the track of the object must be provided in
short time to the search and rescue group in order to delimit the search area, optimize the available
SAR units to be exploited and start the operations, maximizing the probability of success.
From a modelling point of view, this is a similar problem to the assessment of the path of
accidental oil spills (Sebastião and Guedes Soares, 2003) or the trajectory of icebergs (Korsnes &
Moe, 1994).
In all these causalities the factors that strongly influence the evolution of the scenario are the realtime
and predicted wind (Breivik et al., 2011), the near-surface current (Hackett et al., 2006) and the
waves (Röhrs et al., 2012), which cause the drift of the object. Thus quickly available and wellorganized
information about those factors can be determinant in the success of the operation.
Information regarding the sea temperature to estimate the survival time (if people are on the water)
and the visibility can improve the awareness in the allocation of recourses.