From above, Arctic ice looks quite different in summer than it does in winter. A sheen of white covers most surfaces in winter due to snowfall and frigid weather. As temperatures rise in the summer, turquoise splotches of color begin to speckle the ice surfaces. The splashes of blue are melt ponds, areas where snow has melted and pooled in low spots on glaciers and sea ice. A digital camera on NASA's ER-2 airplane captured this top-down view of a melt pond atop a glacier in southeastern Alaska on July 16, 2014. Chunks of ice float on the pond's turquoise water. When it took this photograph, the ER-2--a civilian version of the Air Force's U2-S reconnaissance plane--was flying at 64,000 feet (20,000 meters), about twice as high as a commercial jet.