Southern giant petrels as indicators of ocean surface currents

A southern giant petrel was satellite tracked during a long foraging trip. While presumably at rest on the sea surface, the giant petrel drifted in a counterclockwise corkscrew pattern that is characteristic of an inertial oscillation in the Southern Ocean. This note demonstrates that tracking data from resting seabirds, like giant petrels, can be used as passive drifters to estimate ocean surface currents in a notoriously stormy environment where data near the air-sea interface is difficult to obtain.