In the National Geographic article, "Hole the Size of Maine Opens in Antarctica Ice" by Heather Brady, tells the audience of the mysterious hole as big as the state of Maine that has been spotted in Antarctica’s winter sea ice cover. This is the first time scientists have observed a hole of this magnitude since the 1970s. Known as a polynya, this year’s hole was about 30,000 square miles at its largest, making it the biggest polynya observed in Antarctica’s Weddell Sea since the 1970s. The deep water in that part of the Southern Ocean is warmer and saltier than the surface water. Ocean currents bring the warmer water upwards, where it melts the blankets of ice that had formed on the ocean’s surface. That melting created the polynya. Since the hole continually exposes the water to the atmosphere above, it is difficult for new ice layers to form. When the warmer water cools, on contact with the frigid temperatures in the atmosphere, it sinks. Then it reheats in deeper areas, allowing the cycle to continue. Scientists aren’t sure what this polynya will mean for Antarctica’s oceans and climate, and whether it is related to climate change.
news.nationalgeographic.com/2017/10/sea-ice-hole-antarctica-southern-ocean-spd/
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