Even more amazingly, it wasn’t until the mid-2010s that Antarctic sea ice reached record levels. trebleThere has been a slight but steady increase since 1979, at least at the highest since satellite observations began.
The recent growth of Antarctic sea ice is in stark contrast to Arctic sea ice, which is currently warming up to four times faster than the rest of the planet and has been steadily losing ice over decades. target. This is due to a phenomenon called arctic amplification. As the ice melts, it exposes darker waters and land, absorbing more solar energy than white ice, resulting in more warming.
Antarctica is a different creature. Antarctica is a frozen continent surrounded by open sea, while the Arctic is a sea of ice floes surrounded by land like Russia, Alaska and northern Canada. Antarctic ice is in some sense isolated by the strong, cold currents that swirl around the continent. Additionally, Antarctica’s very high altitude provides an additional cooling effect.
Antarctic sea ice, which forms when seawater freezes, differs from continental ice sheets and ice shelves. Ice sheets lie on land and can be thousands of feet thick. When it begins to float in coastal waters, it becomes an ice shelf. While the Antarctic ice sheet and shelf are indeed deteriorating as the planet warms, continental sea ice is highly seasonal, increasing and decreasing dramatically from winter to summer.
Loss of sea ice does not raise sea level. It’s the same as ice cubes floating in a glass of water melting and not causing the glass to overflow. (The ice is already displacing water.) But sea ice plays a key role in keeping Antarctica’s giant ice shelves from deteriorating, and sea levels could rise dramatically if they collapse. There is If completely melted, Thwaites Glacier, also known as Terminal Glacier, could rise 10 feet in sea level. Sea ice protects Thwaites Glacier and other glaciers because it acts like a buffer, absorbing wind and wave energy that would otherwise erode it. It also cools the air passing over coastal waters, further preventing the melting of ice shelves.
This year, the coast of West Antarctica has seen a particular decrease in sea ice. “This is where climate scientists are most concerned about the potential for ice sheets to contribute significantly to global sea level rise,” Maxim says. “This year there is no sea ice at all in that area, which I think is pretty much the first time. There are also some previous studies that have shown that
But this is not the only global impact of the loss of sea ice. When seawater freezes into ice, the remaining dense brine sinks to the bottom, creating deep currents that rush away from Antarctica. The less sea ice, the weaker the currents. “This will affect the efficiency with which the ocean distributes energy, which will ultimately affect global climate,” says Marilyn Rafael, a geographer at the University of California, Los Angeles who has studied the area. To tell. “What happened in Antarctica doesn’t stay in Antarctica.”
