Light paths of seabirds soaring over the ocean surface enable measurement of fine-scale wind speed and direction
Résumé
Ocean surface winds are an essential factor in understanding
the physical interactions between the atmosphere and the ocean.
Surface winds measured by satellite scatterometers and buoys
cover most of the global ocean; however, there are still spatial
and temporal gaps and finer-scale variations of wind that may be
overlooked, particularly in coastal areas. Here, we show that flight
paths of soaring seabirds can be used to estimate fine-scale (every
5 min, ∼5 km) ocean surface winds. Fine-scale global positioning
system (GPS) positional data revealed that soaring seabirds flew
tortuously and ground speed fluctuated presumably due to tail
winds and head winds. Taking advantage of the ground speed
difference in relation to flight direction, we reliably estimated
wind speed and direction experienced by the birds. These birdbased
wind velocities were significantly correlated with wind velocities
estimated by satellite-borne scatterometers. Furthermore,
extensive travel distances and flight duration of the seabirds enabled
a wide range of high-resolution wind observations, especially
in coastal areas. Our study suggests that seabirds provide a
platform from which to measure ocean surface winds, potentially
complementing conventional wind measurements by covering spatial
and temporal measurement gaps.