A surface current field (arrows) measured by the HF radars at Petten and
Voordijk with colour-coded depths in the background. A coastal jet can be
observed, which can be interpreted as part of the "coastal river" due to
fresh water input into the North Sea mainly by the Rhine River. This water
is transported along the Dutch coast to the north by the residual current.
The red arrows are in regions where interference affected the radar
measurements at the Petten site. The three red stars indicate the positions
of directional waverider bouys, which will be used to evaluate the WERA