At neither the North nor South Pole does the sun rise more than 23.5 degrees above the horizon, and most of the light cast is reflected by the bright white surface. But the South Pole is the colder because of its height: It reposes on top of a very thick ice sheet, which itself sits on a continent, rising as much as 9,843 feet above sea level. The North Pole, by contrast, rests in the middle of the Arctic Ocean, where the surface of floating ice rides only a foot or so above the surrounding sea. The Arctic Ocean also preserves heat, warming the atmosphere in winter and drawing heat from it in summer.