FYFD

Tag: albedo

  • Blue Jewels and Gray Haze

    Blue Jewels and Gray Haze

    Beginning in early spring, brilliant blue ponds form on Greenland’s ice sheets as meltwater gathers in indentations. This satellite image shows the ice east of Nordenskiöld Glacier, which is the tongue of ice projecting on the left side of the image. The center region of ice is darker, marked by soot, ash, and dirt left behind after previous ice layers have melted. These darker remains make the ice less reflective to sunlight; with less reflectivity, the ice absorbs more sunlight, melting faster. (Image credit: M. Garrison/NASA Earth Observatory)

    A satellite image of Greenland's ice sheet, showing jewel-toned blue meltwater ponds to the right, a haze of dirty ice in the center, and bare rock and open water to the left.
    A satellite image of Greenland’s ice sheet, showing jewel-toned blue meltwater ponds to the right, a haze of dirty ice in the center, and bare rock and open water to the left.
    Fediverse Reactions
  • Disappearing Sea Ice Ridges

    Disappearing Sea Ice Ridges

    As blocks of sea ice shift and float, they can press together, forming ridges spaced every few hundred meters or so. A new study uses aerial observations from recent decades to show that these sea ridges are getting smaller in both size and number, a smoothing of Arctic topography that has many consequences.

    The team showed that the overall changes in the sea ridges correspond to a loss of older sea ice. The current smoother sea ice presents less drag to winds and currents, which might suggest that the ice is slower-moving, but instead the opposite seems true. Scientists are not sure why the ice is moving faster, though faster ocean currents may play a role.

    Another consequence of smoother sea ice is wider, shallower melt ponds each summer. These wider ponds increase the amount of sunlight the ice absorbs, hastening melting even further. (Image credit: USGS; research credit: T. Krumpen et al.; via Eos)

  • Albedo Effect

    Albedo Effect

    Temperature isn’t the only factor that determines how ice will melt. In this photo, a dark oak leaf absorbed more solar radiation than the reflective ice around it, causing the ice beneath it to melt. Scientifically, this effect is described by albedo; darker, more absorptive surfaces like the leaf have a lower albedo, whereas light, reflective ice and snow have a high albedo and can better resist melting on sunny days. (Image credit: K. James; submitted by Kam-Yung Soh)