This morning the tide was coming in up the Eden backed by a strong wind. As we walked downstream, the water stopped flowing out to sea. Instead we found a patch of choppy water where the waves didn't make any progress. Stationary waves form when two sets of waves travelling in opposite directions run into each other. In the lab, these have to be of same speed and frequency. I doubt that's strictly true here. In such a stationary wave pattern, I wonder how deep it goes down and whether there is a net flow of water below. It would need to be out to sea because otherwise the water down the Eden would spill over the sides. Also whether the particles at the surface move through the pattern in equal numbers in opposite directions or whether they are stalled and vibrating up and down.
