Apparently as the Arctic grows darker, the Earth grows warmer. At least that is the conclusion of a new research study done on the Arctic which states that it does not look like it used to. It seems that the Arctic is no longer as bright and white as it once was. This is supposedly due to an increased amount of ice melting into the ocean and is helping lead to more global problems. As it becomes darker, the water during summer reflects less of the heat from the sun. Therefore, the Earth is absorbing more warmth than was originally believed. As ice cover disappears, that is what causes the darker appearance. The darkening is creating a way for more solar energy to be taken in.
The North American research team which did this study used information from a report called the Clouds and Earth’s Radiant Energy System to analyze what changes in the Arctic albedo are related to fluctuations in ice cover from the ocean. By looking at the measurements of CERES, NASA satellites were able to study on how the albedo was fluctuating with unparalleled detail.
Since the 1970’s the Arctic has heated up by nearly four degrees Fahrenheit. Such an event has caused the summer time amount of ice cover to lessen by just under 41 percent thus making the area to have a lesser percentage of albedo. Albedo itself is measured by percentage rank. A totally black surface has an albedo rating of zero percent while a totally white region would be measured at 100 percent. The albedo of new fallen snow usually rates between 85 and 90 percent while the ocean is only about 40 percent. It is believed that the albedo of the Arctic has dropped from around 53 to just under 49 percent since the late 1970’s.
Kristina Pistone, who is one of the authors of the Arctic research study and is also a graduate student explained in a press release that it was fairly instinctive to expect that having the white, reflecting sea ice change to a darker ocean surface would raise the amount of heating on the Earth. By studying satellite measurements of both albedo and sea ice in the region, the team was able to confirm what was going on and they also were able to see how much extra heat the area has taken in because of the ice loss.
In the prior studies, by combining computer models and observation, the total amount of energy absorbed by the Earth was estimated. However, this time researchers took a different route. Climate scientist Veerabhadran Ramanathan had previously conducted comparable research studies on the global darkening effects from aerosols but stated that this was the very first time that the darkening effect has been studied over the scale of the whole Arctic. The results that were obtained from the study show very plainly that the warming from the albedo changes has caused receding sea ice in the Arctic to be very large.
The research study was the first to actually use direct satellite measurements in order to examine the changes of the albedo. The researchers discovered that the surface darkening is occurring around three times faster than once believed and is much more serious than past studies have been showing. The study was printed up in the journal PNAS.
The research study has discovered that the Arctic does not look like it used to because it is no longer as bright and white as it once was. This is due to more ice melting into the ocean and is helping lead to other global problems.
By Kimberly Ruble