Tag Archives: kelvin

Antarctica’s glaciers are melting so fast, you can swim in them. In a Speedo.

Even as someone who spends most of her time thinking about climate change, it’s easy for me to forget about the looming danger of changes happening at the bottom of the earth. But Lewis Pugh, a British endurance swimmer and ocean advocate, doesn’t want anyone to forget about the melting glaciers of Antarctica, and to get our attention, he decided to go for a swim.

On January 23, Pugh, who’s 50, became the first person to swim in one of the supraglacial lakes of East Antarctica. These are lakes and rivers that form on the surface of thick glacial ice as it melts from above. A study of supraglacial lakes in Antarctica published last fall found more than 65,000 of them at the peak of the summer melt season in January 2017. Most of the lakes were spotted on the ice shelf, the part of the glacier that hangs over the ocean and is not grounded on the seafloor, making it more vulnerable to calving (i.e., falling off).

In nothing but a swim cap and a Speedo, Pugh dove into water that was just above 32 degrees F and swam for 10 minutes. As he navigated the channel, a chunk of ice cracked and sent an ominous “boom” through the water.

“I swam here today as we are in a climate emergency. We need immediate action from all nations to protect our planet,” Pugh told the BBC. The stunt was part of a larger campaign to create a marine protected area in East Antarctica.

Kelvin Trautman

Kelvin Trautman

Kelvin Trautman

Pugh’s icy swim wasn’t the only first near the South Pole this month. Across the continent, in West Antarctica, scientists deployed at the Thwaites Glacier made the first observations of a pool of warm water melting the ice from below. Scientists drilled through the ice right near the “grounding zone,” the boundary between the part of the glacier that’s resting on the seafloor and the part of it that extends over the open ocean, forming a shelf. They measured temperatures below the ice of more than 2 degrees F above the freezing point of the seawater.

“The fact that such warm water was just now recorded by our team along a section of Thwaites grounding zone where we have known the glacier is melting suggests that it may be undergoing an unstoppable retreat that has huge implications for global sea-level rise,” said David Holland, director of New York University’s Environmental Fluid Dynamics Laboratory, in a press release.

The Thwaites Glacier, which is about the size of Florida, holds the rest of the West Antarctic Ice Sheet together. The collapse of Thwaites alone could lead to about 3 feet of sea-level rise. If you, like me, don’t think about melting glaciers nearly enough, here’s a helpful tool from NOAA that will help you visualize what your neighborhood will look like if that happens.

In addition to the temperature measurement, scientists also sent a camera down to the grounding zone for the first time and captured footage of the ice melting from beneath. “There are a few places where you can see streams of particles coming off the glaciers, textures and particles that tell us it’s melting pretty quickly and irregularly,” Britney Schmidt, a glaciologist at the Georgia Institute of Technology, told the Atlantic.

Antarctica’s glaciers are melting from above and below, like a Popsicle that you just can’t lick fast enough to keep under control.

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Antarctica’s glaciers are melting so fast, you can swim in them. In a Speedo.

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Look At These Crazy Wave Clouds!

Mother Jones

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Look! In the sky! It’s a bird! It’s a plane! It’s a cloud that looks like neither a bird or a plane! A wave! It looks like a wave!

High above South Carolina yesterday “wave clouds” rippled through the sky. They are bonkers!

Look at this video:

Now look at this one:

Weather.com has a whole gallery of crazy shots.

What is a wave cloud? WIRED explains:

These crazy clouds that look like a row of crashing waves are known as Kelvin-Helmholz waves. They form when two layers of air or liquid of different densities move past each other at different speeds, creating shearing at the boundary.

“It could be like oil and vinegar,” Chuang said. “In the ocean, the top is warm and the bottom is really cold. It’s like a thin layer of oil on a big puddle of water.”

When these two layers move past each other, a Kelvin-Helmholz instability is formed that is sort of like a wave. Parts of the boundary move up and parts move down. Because one layer is moving faster than the other, the shear causes the tops of the waves to move horizontally, forming what looks like an ocean wave crashing on the beach.

“It really is like breaking waves,” Chuang said. “A wave breaks when the water on top moves so much faster than the water below that it kind of piles up on itself.”

The world is a weird and beautiful place.

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Look At These Crazy Wave Clouds!

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