Update: Mystery solved!
Today I noticed a large number of little snow puff balls outside. First I couldn’t figure out where they came from. After a while I did notice many of them just being blown across the ground like tumbleweed. It seems, that in calm conditions a light snow fuzz builds up on the surface. If this is followed by just the right amount of wind (currently around 10 knots) it just takes a small seed to start a puff ball, which will grow as it rolls across the Antarctic plateau.
In the seven second video you can see the little puff ball tumbleweeding across the ground until it hits an obstruction and breaks up.
[tags]Antarctica, South Pole, Puff Balls[/tags]