Sea Ice: Fraction and Solar Radiation Absorption
While sea ice is mostly white and reflects the sun's rays, ocean water is dark and absorbs the sun's energy at a higher rate. A decline in the region's albedo - its reflectivity, in effect - has been a key concern among scientists since the summer Arctic sea ice cover began shrinking in recent decades. As more of the sun's energy is absorbed by the climate system, it enhances ongoing warming in the region, which is more pronounced than anywhere else on the planet.
Since the year 2000, the rate of absorbed solar radiation in the Arctic in June, July and August has increased by five percent, said Norman Loeb, of NASA's Langley Research Center, Hampton, Virginia. The measurement is made by NASA's Clouds and the Earth's Radiant Energy System (CERES) instruments, which fly on multiple satellites.
While a five percent increase may not seem like much, consider that the rate globally has remained essentially flat during that same time. No other region on Earth shows a trend of potential long-term change.
When averaged over the entire Arctic Ocean, the increase in the rate of absorbed solar radiation is about 10 Watts per square meter. This is equivalent to an extra 10-watt light bulb shining continuously over every 10.76 square feet of Arctic Ocean for the entire summer.
As a region, the Arctic is showing more dramatic signs of climate change than any other spot on the planet. These include a warming of air temperatures at a rate two to three times greater than the rest of the planet and the loss of September sea ice extent at a rate of 13 percent per decade.
CERES instruments fly on the Terra, Aqua and Suomi-NPP satellites, and one is scheduled to fly on the next orbiter of the Joint Polar Satellite System, a NASA-NOAA effort. The Terra satellite launched Dec. 18, 1999, and CERES first started collecting Arctic data in 2000 so 2015 will mark 15 continuous years of CERES measurements over the Arctic.
This sea ice dataset consists of only three frames that should be slowly moved through. Using the SOS Remote Application step through them at your own pace using the forward button rather than the play button that is used for most datasets. The first frame shows the sea ice minimum extent, taken in August of 2013. The second frame shows the change in sea minimum extent between 2000-2014. The third frame shows the change in absorbed solar radiation as a result of the change in albedo (amount of solar energy reflected back to space) that happens when a white surface turns darker - when ice turns to ocean water - and reflects less sunlight back to space.
For more information about this dataset go to NASA Scientific Visualization Studio.
- This dataset should be stepped through, one frame at a time, using the forward button on the SOS Remote Application.
- The first frame shows the sea ice minimum extent, taken in August of 2013.
- The second frame shows the change in sea minimum extent between 2000-2014.
- The third frame shows the change in absorbed solar radiation as a result of the change in albedo (amount of solar energy reflected back to space) that happens when a white surface turns darker - when ice turns to ocean water - and reflects less sunlight back to space.