Mapping snow distribution in the Alaskan Arctic using aerial photography and graphic relationships

A method is presented for mapping the end-of-winter snow distribution in th e Arctic using vertical aerial photographs taken during the melt. The photo s show a limited number of distinctive snowmelt patterns that arise reliabl y year after year. Data and results from an energy balance melt model indic ate that the patterns are not caused by differential melt but instead repre sent areas of distinctive end-of-winter snow depth. A map of these snowmelt patterns-is thus a map of the end-of-winter snow distribution. Because win d transport of snow is common, the patterns are closely related to the topo graphy. Rules based on this pattern-topography relationship are developed a nd used to map the snow cover directly from topographic maps for three area s covering similar to 220 km(2) of the Kuparuk Basin in northern Alaska. An alysis of the snow maps suggests that about 75% of the area was mapped corr ectly. Applicability, reliability, and limitations of this mapping approach are discussed.