Weddell Polynya

[1][2] The formation of the polynya exposes relatively warmer ocean waters (at surface freezing temperatures of –1.9 °C) to a cold atmosphere, leading to a large exchange of heat which drives deep convection in the ocean, often reaching depths of 1,000 to 2,000 meters.

[4] These were the first three austral winters observed by the Nimbus 5 Electrically Scanning Microwave Radiometer (ESMR).

[7] Since the 1970s, the polar Southern Ocean south of the Antarctic Circumpolar Current has freshened and stratified, likely a result of anthropogenic climate change.

[8][9] More recently, it was found that intense cyclones occurring over the ice pack, far south from the ice edge, were at the origin of the reoccurrence of the Weddell or Maud Rise Polynya in austral winter 2017.

[10] In certain winter months, the general atmospheric circulation around Antarctica exhibits a strong zonal wave 3 pattern, which favors the development of polar cyclones closer to the coast, that is, over preconditioned oceanographic areas for polynya formation, such as the Weddell Polynya in the Lazarev Sea and the Cosmonaut polynya in the Cosmonaut Sea around Antarctica.