On a bike tour with my friend Frauke in Greetsiel two or three weeks ago, she pointed out how well one could see that the waves on the puddles left in the Wadden Sea close to low tide were wind-generated. That was that for the bike tour — now I had to take pictures.

Below you nicely see the ripples that are created where there are longer stretches of puddle aligned with the wind direction, i.e. where there is enough fetch. And you see how the waves get diffracted behind topography, fanning out downwind of slits! The wind is coming from the right here, almost in the direction pointed out by the looks-like-an-arrow-but-is-plastic marine litter.

Here we are looking in the opposite direction, the wind now going left-to-right. Do you see the one slit in the lower half of the picture and how wave crests propagate almost perpendicularly to the wind direction, just because there are waves going through that slit? Pretty cool, me thinks!

The really shallow water with all the stones in it made it really easy to look at waves from different directions. Below, we are looking downwind, at the back of the waves.

And below we are looking upwind. See how different things look now? You still see the wind pushing the waves, the front slope of the wave is a lot steeper than the back slope.

I love the picture above, makes me want to put my hand in the water and play with the waves :-)