Rare ‘Dragon Skin’ Spotted In Antarctica: Why Does This Kind Of Sea Ice Occur?
Antarctica's ancient ice has given researchers sailing the Ross Sea a sight to remember.
Scientists aboard the U.S. icebreaker research vessel Nathaniel B. Palmer stumbled upon uncanny ice formations that resemble dragon scales.
The team, made up of 27 scientists from eight different countries, set course for Antarctic polynyas in the Ross Sea and Terra Nova Bay, as part of the PIPERS expedition.
Polynyas are areas of open water that act as ice factories, where the researchers are planning to investigate how ice forms during the autumn-winter season.
Among them is Dr. Guy Williams, a polar oceanographer from the Institute for Marine and Antarctic Studies or IMAS at the University of Tasmania in Australia.
What Is 'Dragon Skin' Ice?
This rare type of sea ice is known as "dragon skin" and was encountered quite early in the still ongoing research expedition, which only began on April 10.
The strange ice formation was discovered in the Terra Nova Bay polynya, in the Ross Sea of West Antarctica.
Although mesmerizing through its unique features, the presence of dragon skin ice out in the open water is a sign of trouble.
"Dragon-skin ice is very rare, bizarre, evidence of a darker chaos in the cryospheric realm," said Dr. Williams in an IMAS news release.
The cryosphere refers to the parts of the planet's surface where water is frozen. Dr. Williams's ominous statement suggesting this process may be experiencing turmoil brings into question how the peculiar ice formations — an Antarctica mystery — appeared, especially since, as Dr. Williams remarked, this is the first time dragon skin ice is spotted in Antarctica in the last decade.
How The Rare 'Dragon Skin' Ice Is Formed
Thy mysterious ice formation is typically created by strong "katabatic" winds — downslope winds characteristic only to icy regions.
These winds blast over the polynya, lifting its surface ice and carrying it away. As a result, the water below the surface is exposed to the winds, which freeze it, thereby creating more ice.
This constant uplift and formation of ice results in a scale-like appearance, giving the sea ice its dragon nickname.
According to Dr. Williams, this cycle renders 10-fold the amount of ice normally produced in the coastal polynyas.
"Imagine your standard ice-cube tray, filled once. After a week, you get one tray of ice cubes. But if you empty and refill the tray each night, you get so much more," explained Dr. Williams.
Why Is The Strange Phenomenon Important?
Through their relentless action, the katabatic winds increase the number of ice formations, leading to boosted sea ice growth in the Antarctica.
As Dr. Williams points out, this effect can have a strong impact on the oceans, both locally and worldwide.
Under the brutal force of these winds, when the salty seawater freezes, it becomes freshwater ice. When this new type of ice is formed, the salty brine in the sea water is rejected and falls into the underlying water, making it very cold and dense.
Eventually, the water becomes dense enough to "sink to the abyssal layer of the major ocean basins and kickstart the southern limb of the global overturning circulation," shows the IMAS news release.