Snow camouflage as Hugh B. Cott have echoed his observations, adding that other animals of the Arctic such as musk ox, moose, reindeer, wolverine and raven never become white "even in the coldest parts of their range". Cott noted that both animals that hunt, like polar bear and stoat, and prey animals like ptarmigan and mountain hare, require camouflage to hide from prey or from predators respectively. There is little experimental evidence for the adaptiveness of white as camouflage, though the ornithologist W. L. N. Tickell, reviewing proposed explanations of white plumage in birds, writes that in the ptarmigan "it is difficult
Surface Heat Budget of the Arctic Ocean ice reflects about 80% of the incident sunlight. Seasonal changes in the Arctic result in clear skies and radiational cooling from snow-covered sea ice in the constantly dark arctic winter. In spring, with the return of sunlight, melt pools begin to form and increase the rate of heat absorption from the sun. In the summer, during constant daylight, clouds form which reflect light to the sky, but impede heat flow from the ocean. In order to quantify these effects over a large portion of earth's area—the Arctic Ocean—required a large-scale scientific data-gathering and analysis effort over the span of a