Dune Variety

One topic of Image of the Day was the north polar sand sea and 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 image of the north polar erg was taken at 80 degrees North latitude during Northern summer. This image uses lower resolution to provide contiguous cover of a large area. The dunes have very little remaining frost cover.