Search and rescue at sea aided by hidden flow structures

TL;DR

This paper introduces hidden transient attracting profiles (TRAPs) in ocean surface flows that can be computed from a single snapshot and effectively guide search and rescue efforts by attracting floating objects.

Contribution

The study reveals and demonstrates the utility of TRAPs as hidden flow structures that improve SAR efficiency by attracting objects in ocean surface flows, based on experimental validation.

Findings

TRAPs attract drifters and manikins in ocean experiments

TRAPs are computable from a single velocity snapshot

TRAPs can enhance hazard response strategies

Abstract

Every year hundreds of people die at sea because of vessel and airplane accidents. A key challenge in reducing the number of these fatalities is to make Search and Rescue (SAR) algorithms more efficient. Here we address this challenge by uncovering hidden TRansient Attracting Profiles (TRAPs) in ocean-surface velocity data. Computable from a single velocity-field snapshot, TRAPs act as short-term attractors for all floating objects. In three different ocean field experiments, we show that TRAPs computed from measured as well as modelled velocities attract deployed drifters and manikins emulating people fallen in the water. TRAPs, which remain hidden to prior flow diagnostics, thus provide critical information for hazard responses, such as SAR and oil spill containment, and hence have the potential to save lives and limit environmental disasters.