A huge polynya has suddenly formed in the Antarctic Ocean covered with sea ice in middle of September 2017.
Fig. 1 shows the image of GOSAT/TANSO-CAI with path number 19 on September 25, 2017. A huge hole of the same area as the Netherlands was formed in the Antarctic Ocean covered by sea ice (red rectangle). The hole is called polynya. Fig. 2 shows the images around the Weddell Sea enlarged red rectangle in Fig. 1 from 15th September to 30th November 2017. It shows that a huge polynya called Weddell polynya has maintained until the melting season. Generally, polynya is formed in the coastal area by sea ice advection due to wind and/or ocean current. The huge polynya formed offshore is a rare phenomenon. The huge polynya is not formed in every year. The Weddell polynya was last observed in 1976, when the satellite observation has just started. There are many unknown formation mechanisms of the polynya, and many polar researchers investigate for further understanding.
※The TANSO-CAI image was composed of band2 (674nm) in red, band3 (870nm) in green and band1 (380nm) in blue.
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