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Earth Right Now | August 2, 2016
Greenland on the edge
Where ice meets water at the bottom of the sea.
A person can look at a thing over and over again before finally seeing it for the first time. That’s how I felt standing in front of an Arctic map at the University of Washington in Seattle. I gazed at the northwest coastline of Greenland, north of Baffin Bay, up where the Canadian Queen Elizabeth Islands come close to Greenland.
Of course I’ve looked at Arctic maps before, from a zillion different angles. Normally I’m the one pointing and explaining. “Look at how small the Arctic area is. It’s a shallow sea, mostly surrounded by continents and islands where sea ice forms and gets trapped,” I say, encouraging folks to get as excited as I am about this remote part of the planet that’s chopped up, spread out and distorted by most maps. But this time, standing next to James Morison, senior principal oceanographer from the University of Washington, I was the one listening, looking closely and being amazed.
We were in the hallway of the Applied Physics Laboratory’s polar science wing, taking a break between Oceans Melting Greenland (OMG) science team presentations. The walls were lined with photos of teams out on glaciers, ice drilling equipment, ice sheets of the world and grand ice-covered landscapes. Ice, ice and more ice, and penguins. There were pictures of polar bears and narwhals, too. But Greenland’s jagged coastline had me captivated. The islands, the convolutions, the fjords: phenomenal, mindboggling. I couldn’t take my mind off it.
But the Oceans Melting Greenland team is doing more than looking at maps of Greenland. Way more. “We’re trying to look under the ice,” Principal Investigator Josh Willis told me. “What is the sea floor like under there? What is the interface between where the bottom of the ice sheet reaches out over the seawater and down into the ocean?”
The seawater around 400 meters (1,312 feet) deep is 3 to 4 degrees Celsius (5 to 8 degrees Fahrenheit) warmer than the water floating near the sea surface. And the shape of the sea floor (bathymetry) influences how much of that warm, subsurface layer can reach far up into the fjords and melt the glaciers. The OMG team wants to measure how much of that warm water could be increasing due to climate change.
What will the future hold? Will we see 5 feet of sea level rise … or 10 or 20?
And even though Greenland feels untouched and remote, feels so “Who cares?” we all need to be concerned about its complex coastline and the rapid pace of its melting ice sheet. NASA’s GRACE satellites observed Greenland shedding a couple trillion—with a “t”—tons of ice over the last decade, and the rate of melt is increasing. So that winding coastline and those unfamiliar fjords have already impacted all of us—yes, that means you—undoubtedly, no matter how far away or how far inland you reside.
As each of the dozen or so OMG members took his or her turn updating the team on their most recent topography, temperature and salinity measurements, I noticed a trend. Everyone kept repeating the phrases “never been surveyed before,” “it’s a very tough area,” and “these fjords are so very small, they have no names and have never been visited before.” They are literally exploring these unknown areas in detail for the first time.
My mind drifted off to the edge of that unimaginably complicated winding coastline, that unknown place where ice meets water meets seafloor, where the ice is melting as fast as we can measure. And I had to stop the group to ask why. Specifically, why is it so tough? Why has no one been there before? It turns out this area is difficult to navigate because big chunks of remnant sea ice clog up the water. The crew has to snake in between floating icebergs and weave in and out of the narrow fjords. It’s rather treacherous. And weather conditions can be challenging up there. The other reason this area is so unknown is that the glacier has retreated so recently that the coastline is changing as fast or even faster than we can study it.
Last summer, a small group that included UC Irvine graduate student Michael Wood sailed on the M/V Cape Race deep into some of the most jagged areas around southeastern Greenland, which, according to Co-Investigator Eric Rignot, is the “most complex glacier setting in Greenland.” After more than 7,871 kilometers (4,250 nautical miles) and more than 300 Conductivity, Temperature Depth (CTD) casts, the first bathymetric survey was completed.Over the next five years, OMG will measure the volume of warmer water on the continental shelf around Greenland to figure out whether there is more warm water entering the fjords and increasing ice loss at the glacier terminus.
Here are some details about the OMG plan:
- Every year for four years, survey glacier elevation near the end of marine-terminating glaciers around Greenland’s coastline using NASA’s airborne synthetic aperture radar altimeter GLacier and Ice Surface Topography INterferometer (GLISTIN-A).
- Every year for five years, deploy 250 Aircraft eXpendable Conductivity Temperature Depth (AXCTD) probes to measure temperature and salinity of the waters around Greenland from one of NASA’s G-III aircraft.
- Use a ship with multi-beam sonar to measure bathymetry of the seafloor up very close to the extremely jagged coastline of Greenland, as well as a small vessel with a single beam going up into small places, driving up fjords and getting as close to glaciers as is safe.
- Collect gravity measurements from small planes in Northwest, Southeast and Northeast Greenland to help map the sea floor in places the ships cannot go.
Find out more about Oceans Melting Greenland.
View and download OMG animations and graphics.
Thank you for your comments.
Laura
Oceans Melting Greenland is part of NASA Earth Expeditions, a six-month field research campaign to study regions of critical change around the world.?
TAGS: ICE, SEA, GREENLAND, SOUTHWESTERN COASTLINE
Earth Right Now | March 24, 2016
Greenland is melting and it's time to pay attention
We overlook Greenland ice loss at our own peril. It’s one of the largest contributors to accelerating sea level rise, and in the U.S. alone, nearly 5 million people live in 2.6 million homes at less than 4 feet above high tide. If you happen to be one of them, you should definitely pay attention to Greenland.
Yes, yes, Greenland is melting. You already knew that…probably. And the giant flux of fresh water pouring out of the second largest ice sheet on the planet isn’t slowing down anytime soon. Greenland’s ice melt is actually accelerating. In the last decade alone, NASA’s twin GRACE satellites measured it gushing 2 trillion tons of ice like a fire hose pouring fresh water into the North Atlantic.
But it’s easier to focus on politics, celebrity gossip, reality TV and cat videos than on Earth’s climate. It seems like everyone’s all “Greenland? Who cares. Whatever. Next.” And that upsets me.
Is it really that easy to pretend the effects of global warming don’t exist?
We overlook Greenland ice loss at our own peril. It’s one of the largest contributors to accelerating sea level rise, and in the U.S. alone, nearly 5 million people live in 2.6 million homes at less than 4 feet above high tide. If you happen to be one of them, you should definitely pay attention to Greenland.
Fortunately for all of us, NASA is paying attention to Greenland in a big way. We’re so concerned about the amount of ice loss that we’ve named a Greenland observing expedition Oceans Melting Greenland, or OMG for short, because that's the most appropriate response to the phenomenon.
This week, OMG heads up north on one of NASA’s G-III modified airplanes to continue a five-year mission that will look closely at how warming ocean water interacts with glaciers surrounding Greenland and melts them. The project began this past year by mapping undersea canyons via a ship equipped with an echo sounder. For this next part of the investigation, a radar instrument attached to the bottom of the G-III, called the Airborne Glacier and Land Ice Surface Topography Interferometer (GLISTIN-A), will be able to measure precisely how much the oceans are eating away at the edges of the ice on a glacier-by-glacier basis.
Instrument integration (a fancy word for attaching instruments to planes and making sure they work and don’t come loose) went down at NASA’s Armstrong Flight Research Center, and Principal Invesigator Dr. Josh Willis, Project Manager Steve Dinardo, Co-Investigator Dr. Ian Fenty and I headed there to check it out.
Glaciers on the edge
As the technicians and engineers tweaked fistfuls of wires, we crawled in, under, through and around the aircraft. Then Dr. Ian Fenty (who helped design the flight plan) and I sat aboard our flying science lab and talked ice loss for a while. “We often find that a glacier that’s been retreating a lot might be in 1,000 feet of water,” he explained. “Whereas the glacier that’s not thinning very much is in water that’s only 100 or 200 feet deep.” That’s because the layers of ocean water around Greenland are in a very unique situation, where you have colder fresh glacier meltwater near the surface over salty ocean water that, due to climate change, has been warming. The water found at 600 feet and below is a relatively warm 4 degrees Celsius compared with the surface water, which is just near freezing at 0 degrees. This means that the “primary suspect” behind the acceleration of Greenland’s melting glaciers is the warming ocean waters that can get right up against the edge and interact with the glacier itself.
As the surface of lower elevation glaciers melts, the water percolates through the ice and forms giant subglacial channels, like a river system under the ice. If the ice running through these narrow rivers breaks off, the friction between the glacier and the substrate gets reduced a bit and literally stretches the ice so the glacier thins out. OMG’s GLISTIN-A radar is going to measure the height of the ice. “If we see a change in elevation from one year to the next, we can know how much ice is being lost and how much the movement of the glacier is speeding up.” Over the next five years OMG plans to go back to Greenland to look for more changes.
As I left the hangar and headed home, I thought about how Greenland is such a weird part of the world and how much I hope our society can put aside its troubles so we can work together to preserve it.
Find out more about Oceans Melting Greenland here.
Thank you for your comments.
Laura
TAGS: GREENLAND, EARTH, MELTING, GRACE, ICE, CLIMATE CHANGE, GLOBAL WARMING
Earth Right Now | September 28, 2015
#OhMyGawd: You’re Gonna Lose It When you Hear About Oceans Melting Greenland
This morning when I told someone I’d interviewed NASA oceanographer Josh Willis for this blog, they replied, “Isn’t Josh Willis a climatologist?”
“Aha!” I said. “That’s a problem. Not knowing that Earth’s ocean is responsible for controlling the climate is major. Oceanographers are climatologists.”
I mean, look, the ocean covers 71 percent of the planet’s surface, and 71 percent is like, duh, a lot. The ocean, in fact, is so important that a better name for our planet would have been “Ocean” rather than “Earth” — even though our species spends most of its time on boring old land. #sorrynotsorry, geologists.
And you might not realize this because it’s so familiar, but water is crazy. It has this unusual property, called “high heat capacity,” that gives it the ability to hold a stable temperature. It resists heating and cooling. Water will absorb a lot of energy before it changes temperature even a little bit.
And this property of water, this high heat capacity, is what makes life on our planet possible. It’s also what controls and moderates our climate, which is why our ocean, more than our atmosphere, is responsible for creating a stable climate on Earth.
So this is the reason oceanographers are climatologists. It’s also part of the reason Willis chose to name his new science project Oceans Melting Greenland (OMG). He hopes that people everywhere will recognize the role Earth’s ocean plays in controlling the climate and to say to the world, “Hey! The ocean is eating away at the ice sheet! The ocean is playing a huge role in melting the glaciers; it's melting Greenland!”
Remember I just told you water absorbs a lot of energy before it heats up? Well, humans have added so much energy to the Earth system by burning fossil fuels that we have heated the ocean. And now that we’ve warmed it up, you guessed it: The water is in no hurry to change back, so we’re going to be stuck with this warmer water for a very long time. And, says Willis, “Since Greenland is one of the last two remaining ice sheets on the planet, its fate is intertwined with how much destruction we’re going to have with climate change.” If you just said “OMG,” you would be right.
But if you think scientists know everything there is to know about the ocean, you would be very wrong. Willis and his team want to find out more about the complicated geometry (the shape and depth of the seafloor) around Greenland to understand the interaction between the water and ice so that we can find out how fast the glaciers are melting.
M/V Cape Race ship track for phase 1 of 2015 OMG survey. Credit: Ian Fenty
This summer OMG used a ship, M/V Cape Race, to sail right up the narrow fjords on the continental shelf surrounding Greenland to the places where the 4- to 5-degree Atlantic Ocean water meets the bottoms of the frozen zero degree glaciers. The Cape Race used a multibeam echo sounder to map undersea canyons where the warm seawater comes in contact with and melts the glaciers. Willis followed the ship’s path via smartphone, sitting up in his PJs at two o’clock in the morning and uttering a variety of exclamations, including “OMG, turn left, left!”
Next year, the Cape Race will continue to make its way around Greenland, mapping the depth of the seafloor near the fjords, while Willis joins his team in the field flying on NASA’s G-III plane.
“OMG is a big picture project,” he told me. ”We want to see what’s happening in the ocean on the large scale and what’s happening to the ice sheet on the largest scales.”
In the spring, the NASA aircraft, with Willis aboard, will measure how much Greenland glaciers are thinning using the Glacier and Ice Surface Topography Interferometer (GLISTIN-A) instrument. They plan to deploy temperature and salinity probes in the summer. “In most of these places, there’s been no temperature and salinity data collected,” Willis said pausing, “ever.” Over the next five years, they will continue to monitor the ice sheet, asking, “When the water is this warm, how much ice melts?”
Willis knows “OMG” is a campy name for a NASA mission that makes light of a serious subject. “It’s easier to accept something as a reality when you can laugh at it, and accepting reality is a step towards making a change,” he said, explaining that if he was bummed out about climate change all the time, he would be stuck. “Humor makes it tolerable.”
Hopefully, when you find out about Oceans Melting Greenland, you’ll respond in the only way that’s appropriate: “OMG!”
Find out more about Oceans Melting Greenland here, here and here.
View an infographic about the mission.
Thank you for reading, sharing and commenting.
Laura
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TAGS: EARTH, ICE, GREENLAND, OCEAN, CLIMATE CHANGE