melting // Current TV

Kingdom of the Dwarves: The Junk Secret

Gregan makes a discovery.

TonyDiGerolamo
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18 mile crack seen by NASA in Antarctic glacier

Antarctica is so vast that the pictures give you no sense of scale. The pencil-thin... more

JanforGore
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4 months ago
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Greenland's ice is growing darker

In the past, the bright surface of the Greenland Ice Sheet reflected well over half of the sunlight that fell on it. This reflectiveness helped keep the ice sheet stable, as less absorbed sunlight meant less heating and melting. In the past decade, however, satellites have observed a decrease in Greenland’s reflectiveness. This darker surface now absorbs more sunlight, which accelerates melting.

The map above shows the difference between the amount of sunlight Greenland reflected in the summer of 2011 versus the average percent it reflected between 2000 to 2006. Virtually the entire ice sheet shows some change, with some areas reflecting close to 20 percent less light than a decade ago. The map is based on observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on NASA’s Terra and Aqua satellites. It was produced as part of the National Oceanic and Atmospheric Administration’s Arctic Report Card.

Climate scientists have long expected that Earth’s polar regions will become less reflective as global temperatures rise. Rising temperatures melt snow and ice, and the uncovered terrain—water, vegetation, bare ground—is darker and absorbs more sunlight. The loss of reflectiveness then amplifies the initial warming.

Most of the patterns on the map fit expectations. Warmer, lower-elevation areas of the ice sheet have darkened more than the colder, higher-altitude interior. Each summer, winter snow retreats from the edge of the ice sheet. Dark pools of melt water form on the surface of the ice, and windblown dust and other particles also collect near the surface, making it even less reflective.

But the darkening in the interior is just as remarkable as the changes at the margins, according to Jason Box of Ohio State University, who analyzed the reflectiveness data. The interior is the high point of the ice sheet, nearly two miles above sea level, and there is no visible melting in the summer. So why is the area becoming darker?

The darkening, says Box, is due to changes in the shape and size of the ice crystals in the snowpack. As temperatures rise, snow grains clump together and reflect less light than the many-faceted, smaller crystals (see lower image from a scanning electron microscope). Additional heat rounds the sharp edges of the crystals, and round particles absorb more sunlight than jagged ones.

More at the linkIn the past, the bright surface of the Greenland Ice Sheet reflected well over half of... more

JanforGore
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5 months ago
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Climate change and sea level rise: "An emerging hockey stick"

From site: "Since we have such an active community of armchair oceanographers and... more

JanforGore
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5 months ago
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Slick Snow Science: The Pressure Is Off

As skiers and snowboarders strap on their sticks of choice this winter, few will take... more

Simba_Russeau
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6 months ago
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Glaciers: Then and Now

Video at the link Rivers of ice: Vanishing glaciers Stunning images from high in... more

pdy
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8 months ago
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Small Amount of Subsurface Warming Can Trigger Rapid Collapse of Ice Shelves

An analysis of prehistoric "Heinrich events" that happened many thousands of... more

Kristena
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10 months ago
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Sugar Doesn't Melt -- It Decomposes, Scientists Demonstrate

Flying in the face of years of scientific belief, University of Illinois researchers... more

olivia553
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10 months ago
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Dramatic video of Arctic sea ice melting away before your eyes

This is from the: Snippet from link: OBuoy Project, where real-time telemetry is... more

JanforGore
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10 months ago
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Greenland Massive Flash Flood from Super Volcano Will Affect Ocean Currents and Global Temps (VIDEO)

Every so often the earth chooses to remind us that we really aren't in control of... more

dryeraser
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10 months ago
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Siberian Methane Marks Climate Tipping Point

The global warming meltdown will now accelerate rapidly as methane, which traps much... more

Progresshiv
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1 year ago
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Going Under (Webisode 201)

Produced by students from Middlebury College, this creative piece shows us what could... more

Planet_Forward
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1 year ago
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When the Day After Tomorrow Has Come

Imagine that it is 2050 -- or even 2020 -- and you are the president. Your science... more

GoldenHeart
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Weather Report

This week in Copenhagen, negotiations are going on toward producing a pact to fight global warming, a pact that is supposed to be ready for world leaders to ratify at the end of the week. Whether or not the pact will be completed, or will be strong enough to accomplish what people who want to fight global warming want it to accomplish is unclear at this moment. But it does at least show that the world is trying to contradict that famous saying by someone who may or may not have been Mark Twain: “Everybody talks about the weather, but nobody does anything about it.”

One of the first pieces that I ever shot for Vanguard, back in the summer of 2005, was a story set up by Adam Yamaguchi, looking at the shrinking of glaciers in Alaska.

Glacier (Video)

What we saw was pretty shocking, in terms of weather changing the landscape of Alaska, but as someone who’s been living in Southern California for many years, the idea that the weather can have a big impact on your life wasn’t actually a novel idea. I’m a native of Michigan, and, growing up, it was always my ambition, to leave and move to southern California, sunny southern California, to get away from weather. Ironically, as it turned out.

Certainly, in my adopted state, I can barbeque in my backyard on New Year’s Eve more easily than one can in Michigan—I tried it last New Year’s at my father-in-laws, when it was 10F, and it’s doable, though bracing. But, as it turns out, cold and snow aren’t necessary the kind of weather that can have a big impact on your life.

Here’s where the irony comes in: It stopped raining yesterday in Los Angeles, much to the relief of the people living in my canyon, because the rain ended before the mudslides began. There was a danger of mudslides because the side of the canyon 400 yards from my house was entirely denuded by fire this past August—one of the early fires in what turned out to be nearly a two month siege of them, including the Station Fire, the biggest fire in the recorded history of Los Angeles County. The fires came because it’s been so warm and sunny—and dry.

The fire came into my canyon as I was driving home early from work on what seemed like a pretty great day---as I was driving Laura Ling and Euna Lee were in the air, en route home to LA from North Korea in Bill Clinton’s plane. I saw a plume of smoke from the freeway, and thought to myself, “on this good day, someone else is having a bad one,” and pulled into to my canyon to hear sirens. At first I couldn’t see anything, but then a car with fire department officials pulled in front of me, and four officials got out and looked up at the hillside where there was perhaps a fifty foot wide fire. I drove on into my driveway, and said to me wife, kind of casually, ‘there’s a fire in the canyon.” We stood on our front driveway watching it, and within minutes it was half a mile wide, and very loud—it was crackling like a fireplace in a Christmas commercial. We ended up calling out kids and telling them not to come home, then evacuating our photo albums, dog, turtle, rabbit, guinea pig, my son’s guitars and my daughter’s harp. The next day, we returned—and fortunately no homes in our canyon were hurt. But ever since, the majestic pine in my neighbor’s yard looks like a potential torch of death.

All of which is a long-winded way of saying that in my native Michigan, I felt annoyed and persecuted by the weather, but in my adopted southern California we are sometimes obliged to be afraid of the weather. And that seems to be what they’re debating in Copenhagen, whether or not the world as a whole, in general, should start being afraid of the weather, and, in contradiction of Mark Twain or whomever’s observation, start doing something about it.

Recently on the Vanguard Blog:
- Au revoir from the Vanguard intern - Dan Ucko
- A shout-out to Doctors Without Borders - Kaj Larsen
- Cocaine Mafia: Coke's huge market in Europe and the African supply chain that gets it there - Christof Putzel
- Lining up - Mitch Koss
- Does Sri Lanka offer lessons for Obama? - Darren Foster
- Kaj’s robot and weapon firing skills are put to the test - Lauren CerreThis week in Copenhagen, negotiations are going on toward producing a pact to fight... more