North Polar Erg

One of the topics covered by the Image of the Day was the north polar sand sea and at isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs', an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent,and 2) the individual dunes are large in size and complex in form.
This VIS image was taken at 82 degrees North latitude during Northern spring. The dunes are still partially frost covered. This region is part of the north polar erg (sand sea), note the complexity and regional coverage of the dunes.