Observations of coherent transverse wakes in shoaling nonlinear internal waves

Abstract Space- and time-continuous seafloor temperature observations captured the three-dimensional structure of shoaling nonlinear internal waves (NLIWs) off La Jolla, California. NLIWs were tracked for hundreds meters in cross- along-shelf directions using a fiber optic Distributed Temperature Sensing (DTS) array, complemented by an ocean-wave-powered vertical profiling mooring. Trains propagating cold-water pulses observed on DTS array inshore location polarity transition predicted weakly wave theory. The subsequent evolution signatures during was consistent with that strongly large Froude number, highlighting their potential to impact property exchange. Unexpectedly, individual trailed coherent, small-scale pattern seabed variability as they moved across mid- inner shelf. A kinematic model used demonstrate patterns transverse instability along-crest wavelength ∼10 m – distance comparable cross-crest width wave-core inferred amplitude several meters. signature this is span-wise vortical circulations generated direct numerical simulations breaking waves. coupling between wave-wake turbulent may have important mass, momentum, tracer redistribution coastal ocean.