A giant hole in the sea ice off the coast of Antarctica close to the size of Tasmania could change weather systems in Australia, a Hobart researcher says.
The estimated 55,000sq km hole, known as the Weddell Sea or Maud Rise Polynya, has opened for the third time in 40 years.
A polynya is an area of water surrounded by sea ice formed when warm currents reach the surface.
Antarctic Climate and Ecosystems CRC sea ice scientist Jan Lieser is monitoring satellite data to keep an eye on the hole.
"It's significant that there's an open window to the atmosphere," Dr Lieser said.
"The sea ice keeps a lid on the Antarctic water but if you have a broken lid then you get a heat flux from the warmer water below the ice ... which melted the ice in the first place.
"It changes the heat and momentum of the atmosphere and the ocean. Heating the atmosphere, that changes the system [and] with these heat fluxes you can see changed weather patterns.
"We're not sure if this will reach Australia yet."
A smaller polynya opened up in the same area last year for about two weeks.
A previous occurrence during the 1970s lasted for three years.
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