Nadir photographs taken during low-altitude transects of the Arctic Network of national park units and Selawik National Wildlife Refuge, Alaska, July 2013

Nadir images taken by automatic time-lapse from a Drift HD-170 (focal length 5.00 mm) and a GoPro Hero3 Black Edition (focal length 2.77 mm) of the arctic landscape during low altitude transects at five second intervals. Transects were conducted from small aircraft over the National Park Service’s Arctic Network (Bering Land Bridge National Preserve, Cape Krusenstern National Monument, Gates of the Arctic National Park and Preserve, Kobuk Valley National Park, and Noatak National Preserve) and the U.S. Fish and Wildlife Service’s Selawik National Wildlife Refuge in northwest Alaska.