Seasonal haloes and fractals. In the spring, as the winter layer of dry ice covering the polar regions sublimates, there is a lot of action. The ice layer cracks and ruptures, and escaping gas lofts sand from the dunes above the layer of seasonal ice.
There are long fans of dust lifted and carried downwind of a rupture. Polygonal cracks are visible by the outline of material released from below the ice. Dark blotches where spring sun has burned off the ice layer entirely, reveal the dark sand of the dunes. Multiple tones within the dark blotches suggest the thinning of the ice layer in various stages of completion.
Beautiful Mars series.