  Vertically 0.042-m-spaced moored high-resolution temperature sensors are used
for detailed internal wave-turbulence monitoring near Texel North Sea and
Wadden Sea beaches on calm summer days. In the maximum 2 m deep waters
irregular internal waves are observed supported by the density stratification
during day-times warming in early summer, outside the breaking zone of <0.2 m
surface wind waves. Internal-wave-induced convective overturning near the
surface and shear-driven turbulence near the bottom are observed in addition to
near-bottom convective overturning due to heating from below. Small turbulent
overturns have durations of 5-20 s, close to the surface wave period and about
one-third to one-tenth of the shortest internal wave period. The largest
turbulence dissipation rates are estimated to be of the same order of magnitude
as found above deep-ocean seamounts, while overturning scales are observed 100
times smaller. The turbulence inertial subrange is observed to link between the
internal and surface wave spectral bands.
