Abstract
The mixing of ocean waters on continental shelves, which is mainly
driven by waves, tides, and currents, plays a key role in the physics,
biogeochemistry, and ecology of coastal regions. This study focuses on
four months of continuous data recorded along a telecommunication cable
offshore Oregon, USA, with Distributed Acoustic Sensing (DAS). We apply
a cross-correlation approach to the continuous DAS data to infer the
propagation of ocean surface gravity waves in the 3 to 100 s period
range and estimate near-surface ocean flows. We observe strong
spatio-temporal variations of ocean flows along the cable over four
months, with strong impacts from a series of storms in late October
2021. We find that our measurements capture oceanic surface motions as
those measured by nearby traditional oceanographic instruments. This
study demonstrates that ocean-bottom DAS can be used to infer the
dynamic properties of near-shore oceans with an unprecedented
spatio-temporal resolution.