Storms have been battering parts of Scotland causing flooding, road closures and closing some schools. The high winds sweeping the country forced foam from the North Sea onto land at Aberdeen's Footdee area at the beach on Tuesday morning.
The spume left cars, streets and houses looking as if they had been hit by a sudden snow storm. "The sea is acting like a washing machine," said Prof Christopher Todd, marine ecologist at the Scottish Oceans Institute at the University of St Andrews.
He said the easterly gales battering the Aberdeenshire coast had led to an "incredible amount of wave action". Prof Todd said that the air had "piled into the water" and mixed up with organic material. He said: "It is likely there are phytoplankton cells and they produce a lot of mucus which when whipped up can form this foam."
Most phytoplankton are too small to be seen but they can form an algal bloom in the spring and, to a lesser extent, in the autumn. The sea foam - or spume - can be quite "stable" when formed and can last a significant period of time, Prof Todd said.
With two additional videos.