Question: Which of the following is a difference between barchan and parabolic dunes? Need Assignment Help? The tips of a barchan dune point into the wind, while the tips of a parabolic dune point downwind. A barchan exhibits a concave slip face, while a parabolic dune shows a convex slip face. A barchan exhibits a convex slip face, while a parabolic dune shows a concave slip face. Barchan dunes are commonly found on the coast, while parabolic dunes prefer hard, bedrock surfaces. Barchan dunes are partially covered by vegetation, while parabolic dunes lack vegetative cover.