Albedo patterns on Triton

A model for seasonal taransport of volatiles based on Trafton (1984) is coupled to considerations of methane photochemistry to infer albedo patterns on Triton's surface at the time of the Voyager encounter. The relatively large southern subsolar latitude at present is predicted to cause the deposition of an extensive fresh frost layer covering approximately the northern half of the planet. Sublimation of Triton's south polar ice has been occurring since 1930, but has been preferentially occurring near the pole. The sublimation of ices in this region may be concentrating dark organic matter on the surface of the ice or exposing layers of this material which have built up in the ice over many seasonal cycles. The south polar cap may be distinctly darker near the pole than around the equatorward edge.