Voyage to an Antarctic polynya sights rare ‘Dragon-skin’ ice—5 May 2017

An autumn voyage to the heart of an Antarctic polynya has rewarded expeditioners on a US icebreaker—including ARC Future Fellow, Dr Guy Williams, from the Institute for Marine and Antarctic Studies (IMAS) at The University of Tasmania—with a glimpse of a rarely seen type of sea ice. The sighting of ‘Dragon-skin’ ice was an early highlight of an ongoing voyage to the Ross Sea by the Nathan B Palmer that began in early April, well after most Antarctic expeditioners have departed for warmer climes. Dr Williams is one of 27 scientists from eight countries who are studying the winter behaviour of coastal polynyas—areas of open water against Antarctica that are ‘ice-factories’, with 10 times the average amount of sea ice produced due to the strength of local ‘katabatic’ winds that flow from the interior of Antarctica.

Dr Williams has brought a squadron of fixed-wing unmanned aerial systemswith the aim of augmenting on-ice LIDAR (laser scanning) surveys of the surface topography. “Dragon-skin ice is very rare, bizarre, evidence of a darker chaos in the cryospheric realm, not seen in Antarctica since 2007,” Dr Williams said. “Imagine your standard ice cube tray, filled once. After a week, you get one tray of ice cubes. But if you empty and re-fill the tray each night, you get so much more. That is what the katabatic winds are doing in the polynya, removing the ice, exposing the water and making more ice form.”

Media issued by the Institute for Marine and Antarctic Studies.

Image: ‘Dragon-skin’ ice.
Image courtesy: The Institute for Marine and Antarctic Studies (IMAS).

Original Published Date: 
Friday, May 5, 2017