It was 11:30 in the morning and GLISTIN-A instrument engineer Ron Muellerschoen and I were in northern Greenland at the Thule Air Base pier looking over the frozen Wolstenholme Bay. We’d been talking about the time Ron was wearing shorts here during the summer, but today it was the typical -22 Fahrenheit (-30 Celsius.) And even though over the past week we’d somehow gotten used to the cold and I was wearing a big parka, my legs were starting to get cold after walking for an hour. So we decided to head back.

As we turned around to go, I was struck in the face by the sun’s rays reflecting off the ice-covered ground. The brightness was astounding. And in that instant the meaning of “albedo” was seared into my brain in a way that went beyond reading about the science or looking at illustrations and animations.

There was something special about the experience of having the rays of the sun, which was sitting low in the high latitude sky, hit the ice surface at that extremely low angle and reflect off into my eyes.

Albedo is a measure of how reflective a surface is, how much light energy bounces off and reflects away and how much light energy gets absorbed. (Think hot asphalt on a sunny day. Black asphalt has a low albedo and absorbs light energy, while the brightest white has the highest albedo and reflects the light.)

I stood for a moment, looking at the ground — a hard, dry, crusty mixture of ice and snow that made an exceptionally satisfying crunch crunch noise as our boots marched through it — and tried to figure out the color: 50 shades of white. I settled on white/light blue/silvery sparkle. Due to the low angle of the sun, the tiniest rough edge the size and shape of a pebble on the ground’s textured surface left a long, dark shadow.

No matter where we were or how we stood or what time of day, all day, every day, there were always long shadows — crazy long shadows. At 78 degrees north latitude, a full 12 degrees above the Arctic Circle, the sun will never be overhead. Never. I know that seems unbelievable, but even during the summer solstice, when Earth’s North Pole is tilted toward the sun, or during the four summer months of 24-hour daylight, the sun is always low, low, low at this latitude.

Low on the horizon

In that moment, I also understood another science question that had been bothering me. I’d been wondering why the meter-thick sea ice hadn’t yet begun to melt. Even though it was the end of March, even though the equinox had passed, the sun was out and the days were getting longer. In fact, up here the days were getting much longer, very quickly. On March 23, just three days after the equinox, we were already having 14-hour days with sunsets lasting past 9 p.m. That’s because in these high latitudes, the day length can increase by as much as 40 minutes per day. And by mid-April, just a few weeks after spring equinox, there will be 24 hours of daylight and the sun won’t set again until September. 

By mid-April the meter-thick layer of frozen seawater that covers the sea surface and fills the fjords will completely melt and expose the dark blue ocean underneath. But today, even in this brilliant sunshine, even on this day of 14-hour sunlight, the ocean was still completely frozen over. 

But “Why?” I’d been wondering. Why, with all this extra sunshine, was the sea surface still so frozen? And why did that hard, dry, crusty mixture of ice and snow still remain on the ground?

In that instant, as the glint of the sunlight reflecting off the icy ground hit my face, I knew exactly why. It was the extraordinarily low angle of the sunlight that bounced right off the stunning bright whiteness of the ice. The sunlight was not absorbed by the ice and snow and instead was reflected away. It wouldn’t be until another month or so that the sun would get a little higher in the sky. And although the sun would never be directly overhead up here, it would be high enough to begin melting the ice.

No matter how much a person studies Greenland, or the northern latitudes, or albedo, or Earth in general, going into the field to experience those things can change your entire understanding of the world and how it works. I stood there for a moment, just allowing the high-latitude sun’s cold rays to glance off the snowy ice and shine straight into my face.

NASA’s Oceans Melting Greenland (OMG) team is here in Greenland; here to find out specifically how much ice the island is losing due to warmer ocean waters around the coastline. There is almost no ocean data in remote places like this, but OMG is busy working to change that, studying the complex ocean processes that affect Greenland's coastline because gathering data is critical to understanding Earth’s complex climate. This information will help us understand the amount of sea level rise we're going to have around the world.

Thank you for reading,

Laura

TAGS: EARTH, OCEANS, MELTING, GREENLAND

• 

  ABOUT THE AUTHOR

  Laura Faye Tenenbaum, Science Communicator

  Laura Faye Tenenbaum is a science communicator at NASA's Jet Propulsion Laboratory, teaches oceanography at Glendale Community College and writes the "Earth Right Now" blog for NASA's Global Climate Change website.

"Get to work." The phrase stuck in my head.

I had just walked out of a two-and-a-half-hour debriefing with NASA’s Oceans Melting Greenland (OMG) Principal Investigator Josh Willis, but the whole meeting could be summed up in those three little words of his: Get to work.

It was as though he’d been ringing one of those big ol’ dinner gongs. Data! Hot off the press! Come and get your data! Calling all oceanographers, geologists, paleo-climate scientists: come and get a big ol’ helping of free data.

He made me hungry for data, too.

OMG has just returned from its second spring season. Every April for five years, just before the ice starts to melt, OMG flies a radar instrument over almost every glacier in Greenland that reaches the ocean and collects elevation measurements within a 6.2-mile (10-kilometer)-wide swath for each glacier individually so we can measure how quickly each one is thinning. That’s literally hundreds of glaciers.

“We have more than 70 of these swaths that cover a couple hundred glaciers to create new elevation maps that are high accuracy, high resolution and high quality,” Willis said.

OMG also has bathymetry data from sonar and gravimetry. And we have a year’s worth of Airborne Expendable Conductivity Temperature Depth Probes AXCTD data collected last September plus hundreds of vertical profiles of temperature and salinity taken from ship surveys. “We have temperature measurements in many glacial fjords that have never had a historical temperature profile before. And none of that data is being used to its fullest extent yet.” OMG will set the baseline so we know what the water temperatures are today, and as we look to the future, we can watch them warm. That’s huge. 

I recounted all the times I’ve told someone that many parts of the ocean are still so unknown. I thought about all the times I’ve written about the OMG aircraft flying into remote, uncontrolled airspace, or researching the ocean water-ice interface around Greenland: So many of these places still nameless, still anonymous, still unidentified, still unknown. It’s mind blowing.

And somewhere in all this new data is information about the correlation between the ocean water and the ice as well as the answer to the question of how each glacier may or may not be affected by the waters offshore. “We know that warm water reaches a lot of glaciers. And there have been surveys in few places, but we’ve never had a comprehensive survey of the shelf water before,” Willis said.

OMG is mapping out the edges of glaciers and watching them change year on year on year. The mission measures glacial elevation in the last few kilometers before the glacier hits the water to see exactly how much the glacier shrank or retreated or both. In a few cases, the opposite might happen. Over a single year, a glacier might not have had as much calving or it might have slowed down, which would cause it to thicken and advance.

There are literally hundreds of glaciers to research and dozens of papers buried in that data. And anybody who wants to can sift through it and publish. “You could get a Ph.D. done really fast,” Willis added enticingly. Here are some recommendations for interesting scientific research:

• OMG’s temperature data could be used to write oceanography papers about where the warm water is on the shelf and to map out and catalogue which glaciers terminate in deep Atlantic water and which ones sit in shallow water. OMG has enough data to catalogue the depth of the faces of two-thirds of the glaciers around Greenland.
• Paleo-climatologists and geologists can use new clearly mapped-out OMG bathymetry data to study how ancient glaciers carved troughs in the sea floor. Looking at maps of the seafloor will help us understand the implications for Greenland’s ancient ice sheet. Some flat-bottomed troughs, for example, show evidence of where little ancient rivers must have carved their way through to erode the paleo-glaciers. And sea floor sediments could be analyzed to find out how far the ancient glaciers advanced.
• Overview papers that compare and contrast the east, west, north and south coasts of Greenland would be incredibly useful to have.
• Some elevation maps made from historical datasets as well as a few decades’ worth of temperature measurements already exist for some isolated regions across Greenland. Using these historical maps, it’s now possible to compare them with current measurements of temperature and elevation in these locations to observe the changes.
• OMG is also gathering oceanography data around Greenland. Since the Atlantic Ocean water is very warm and salty and the Arctic Ocean water is cold and fresh, the ratio of those two could be analyzed. Warm Atlantic Ocean water has been in the coastal area around Greenland forever, but how much Atlantic water makes it onto the shelf and reaches the glaciers? This is affected by the bathymetry and the winds, which affect the local currents. And according to Willis, “There’s really still a lot to learn.”

Already there are four downloadable datasets right here! So, come and get it, all you hungry Ph.D. oceanographers.

Get to work.

I can't wait to read your papers,

Laura

TAGS: EARTH, OCEANS, MELTING, GREENLAND

• 

  ABOUT THE AUTHOR

  Laura Faye Tenenbaum, Science Communicator

  Laura Faye Tenenbaum is a science communicator at NASA's Jet Propulsion Laboratory, teaches oceanography at Glendale Community College and writes the "Earth Right Now" blog for NASA's Global Climate Change website.

“What are we doing all the way out here?” I thought. If I looked out the left side of NASA’s modified G-III aircraft, I could see Canada out the window—Baffin Island, specifically, the largest island in Canada, part of its northeast territory. And if I looked out the right side, I could see the west coast of Greenland. We were pretty much halfway between the two, right in the middle of Baffin Bay, and I was surprised.

At a glacial pace

I went over to where Flight Engineer Terry Lee kept the map of all the scheduled drop positions and stared at it for a while. She’d marked with a green highlighter the places where she’d already released science probes through a tube in the bottom of the plane. (Hahahah, yes! There’s a hole in the plane through which Aircraft eXpendable Conductivity Temperature Depth (AXCTD) probes leave the aircraft to travel 5,000 feet down to the sea surface and then another 1,000 meters into the ocean, sending back data as they go.)

I looked out the window as we flew on. Icebergs dotted the seascape. Each one had once been part of a vast ice sheet that’s been around for hundreds of thousands of years. Each one had moved – at a glacial pace, mind you – from the interior, down through one of the many fjords that slice through the Greenland coastline, and finally out to sea, where they would ultimately melt away. The ‘bergs were large, and it was fun to fly over them and look at their perfect whiteness against the stunning blue sea. All of us would gather on one side of the plane as we passed over a ‘berg, and then quickly jump to the other side to look for it again as we passed by it. But even though there were hundreds of icebergs floating around out there, Baffin Bay is vast — more than 250 thousand square miles. So, in the grand scheme of things, the icebergs seemed inconsequential, incapable of affecting the ocean salinity more than a small amount.

Real-time data

As I was listening, I could see temperature and salinity values arriving in real-time on the monitor. “Wow, no way!” I exclaimed. “That’s insane.” All the way in the middle of Baffin Bay, 100 miles offshore, the ocean was fresher on the surface. I watched the salinity values increase as the probe sank. The temperature profile also reflected a scenario of near-zero-degree water at the surface with 3- to 4-degree ocean water below. That upper layer is Arctic Ocean Water, which is way less salty than the warmer North Atlantic Ocean Water that lies beneath it.

I walked back to look at the yellow dots on the map of the scheduled probe drops one more time. We were as far away from the coast as we would be; the rest of the drops were closer to shore. I wondered how the temperature and salinity profiles in the coastal waters would compare to those from the open ocean.

And the point of the mission flooded my mind again. I looked out the window, across the stretch of Baffin Bay at the Greenland coastline, where groups of icebergs dotted the horizon. In this vast expanse, no one’s done this before, no one knows what this ocean water is like, and we are about to find out.

Find out more about Oceans Melting Greenland.

View and download OMG animations and graphics.

Thank you for your comments.

Laura

TAGS: CLIMATE, OCEANS, MELTING, GREELAND, NASA, JET PROPULSION LABORATORY, JPL

• 

  ABOUT THE AUTHOR

  Laura Faye Tenenbaum, Science Communicator

  Laura Faye Tenenbaum is a science communicator at NASA's Jet Propulsion Laboratory, teaches oceanography at Glendale Community College and writes the "Earth Right Now" blog for NASA's Global Climate Change website.

We know more about the moon and other planets than we do some places on our home planet. Remote parts of the world ocean remain uncharted, especially in the polar regions, especially under areas that are seasonally covered with ice and especially near jagged coastlines that are difficult to access by boat. Yet, as global warming forces glaciers in places like Greenland to melt into the ocean, causing increased sea level rise, understanding these remote places has become more and more important.

This past spring, Oceans Melting Greenland (OMG) Principal Investigator Josh Willis led a team of NASA scientists to begin gathering detailed information about the interface between Greenland’s glaciers and the warming ocean waters that surround them. The next step in accessing this extremely remote region involves dropping a series of Airborne Expendable Conductivity Temperature Depth, or AXCTD, probes that will measure ocean temperature and salinity around Greenland, from the sea surface to the sea floor. With this information, they hope to find out how quickly this warmer ocean water is eating away at the ice.

Since no one has ever dropped AXCTDs through a tube at the bottom of a modified Gulfstream-III, the OMG team headed to Ellington Field Airport near NASA’s Johnson Space Center in Houston, Texas, for a test drop into the Gulf of Mexico. I went along for the ride.

"In position!"

Expert NASA T-38 pilot Bill Rieke executes his flight plan to rendezvous with the Oceans Melting Greenland (OMG) scientists and engineers aboard NASA’s modified Gulfstream-III at “drop one.” As soon as photographer James Blair is ready with his high speed and high definition cameras, he calls out “In position!” from the supersonic jet to the team in the G-III over Very High Frequency (VHF) radio. 

The money shot

It’s up to Derek Rutovic, G-III program manager at NASA’s Johnson Space Center, to visually inspect the release of the AXCTD to make sure it does not impact the plane and then to see that the parachute opens. The first test drop was released while the plane was flying at a height of 5,000 feet and a speed of 180-200 knots. 

Temperature and salinity

Alyson Hickey and Derek Rutovic prepare the AXCTD tubes for deployment. After these test flights are complete, the mission heads up to Greenland this fall, where the AXCTDs will measure temperature and salinity around Greenland to make a detailed analysis of how quickly the warmer waters around Greenland are eating away at the ice sheet.

3, 2, 1 ... drop!

G-II pilot Bill Ehrenstrom calls out “Three, two, one, drop!” over the Very High Frequency (VHF) radio channel to signal Rocky Smith, who then pushes the AXCTD tube through a hole in NASA’s modified Gulfstream-III. Rocky then announces, “AXCTD is clear.” 

AXCTD sails down

Oceans Melting Greenland (OMG) Project Manager Steve Dinardo and OMG Principal Investigator Josh Willis wait for a radio signal as the AXCTD sails down through the air to indicate it’s arrived at the sea surface. Once it hits the sea surface, it releases its probe, which travels through the ocean to the sea floor and sends ocean temperature and salinity data up to the team in the aircraft above, who monitor the data in real time. 

The flight path

Both aircraft must execute a complex flight path, which involves filming two precision AXCTD test drops minutes apart.

Details, details, details

To execute the precision flying required to photograph the test drop of a series of AXCTDs, the team is briefed before and after all flights, where every detail is explicitly coordinated. From left: Flight Engineer Alyson Hickey, Oceans Melting Greenland Principal Investigator Josh Willis, photographer James Blair, Oceans Melting Greenland (OMG) Project Manager Steve Dinardo and NASA Gulfstream-III Program Manager Derek Rutovic.

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: OMG, TESTING, WATERS, OCEANS, MELTING, GREENLAND

• 

  ABOUT THE AUTHOR

  Laura Faye Tenenbaum, Science Communicator

  Laura Faye Tenenbaum is a science communicator at NASA's Jet Propulsion Laboratory, teaches oceanography at Glendale Community College and writes the "Earth Right Now" blog for NASA's Global Climate Change website.

Hey, readers: Our team reads your comments. We share them at our meetings. Sometimes they make us laugh, or sigh, or even scratch our heads.

We see that you see us. Yay for connecting!

And this is how I know you’ve noticed NASA’s latest airborne campaign, where NASA scientists fly a bunch of NASA instruments on a NASA airplane to study more details about Earth. Cool, right?

Lately, we’ve been flying around the edge of Greenland collecting radar data about how much its glaciers are melting into the sea. And the most common comment we get goes something like “Wheee! Let’s go. Take me with you.” When I told a friend about the possibility of joining the team in the field, she exclaimed, “All expenses paid?”

HAHAHA … no. As if a NASA expedition to Greenland is like a resort vacation instead of a giant heaping pile of hard work.

“When I looked down at the rivers of ice running into the ocean, it was shocking to think about the effects of rising sea levels as far away as California or Antarctica,” said Principle Investigator Josh Willis, two days after returning from his first trip to observe this pristine part of our planet as it melts into the sea and goes bye-bye. “Yet, I had a blast.” Because even though we all probably have many complex emotions about climate change, ice mass loss and sea level rise, we can still simultaneously feel super duper stoked about the chance to fly over the glaciers of Greenland in a freaking NASA plane. “The mountains, the ice, the water and the ice in the water are incredibly striking even though it’s lonely to see it disappearing at the hands of human activity,” he told me.

Yes, emotions are weird, and yes, there’s an awkward contrast or odd juxtaposition between feeling both thrill and grief at the same time.

But that’s life, I guess.

So just in case you’re still envisioning a champagne-swilling, caviar-scoffing, gangsta, hip-hop music video scene, here are a few things that might surprise you about the kind of major effort it takes to get on board NASA’s G-III plane and join the Oceans Melting Greenland field campaign:

Kick booty in a fire-resistant flight suit

So, you think you’d kick some booty in one of these flight suits? Oh, yeah. Totally. Well, so do we. Would you kill to have one? But the real reason the pilots think they’re so fab is because they’re fire-resistant. They. Resist. Fire! With racks and racks of science equipment wired with electrical cables, the crew has to be extra careful about fire on the plane. So wearing one of these flight suits is required.

A load of gas and no mistakes

A trip to Greenland sounds all romantic ‘n’ stuff, but operating a science instrument aboard a flying science lab on a six-hour flight every day is hard work. Just check out these flight paths. According to Project Manager Steve Dinardo, “You get a full load of gas and no mistakes.” Notice the flight path zigzags across the complicated coastline of the entire island. That’s because global warming of Earth’s atmosphere is melting the top of the ice sheet. But, aha! The ocean water around Greenland is even warmer than the air. That warm water is busy melting the glaciers from around their edges, hence the name, Oceans Melting Greenland, which will find out exactly how much of this melting is going on.

Instruments, instruments and more instruments. And did I mention some serious training?

The NASA modified G-III aircraft is … modified. (Did you notice the word “modified”?) What modified means is the plane has holes in it so experimental science instruments can stick out. And more scientific instruments are attached in, under and onto the plane in all sorts of configurations. To get to fly on this baby, you’d better have some training. Yep, some serious training: Safety training, first aid training, survival training. You get the idea.

Keep warm, in style

I can work the runway like a glamazon in this red coat, but it’s rated for survival in 50 degrees below zero. I said survival. In case of emergency. Does this sound like your all-inclusive vacation package now? With a survival coat? And there’s a survival vest too, with a beacon attached, and food rations, a pocketknife tool set, fishing gear, first aid supplies, a radio and a laser pointer for playing with cats—oops, I mean for signaling emergency and attracting rescue. The thing weighs about 20 pounds. Everyone on the plane has one of these puppies, and you’d better believe they know how to use it. If there’s a problem, the team would have to survive three to five days out in the wilderness until they're rescued. I don’t mean to scare you, but at NASA, when we say we care about safety, we’re not messing around.

“It’s not a triumph of human achievement that we’re melting the ice sheet,” said Willis. “When you see how huge these glaciers are and this huge chunk of this ice sheet disappearing into the ocean, it’s almost incomprehensible even when you see it from 40,000 feet.”

Wheee.

Find out more about Oceans Melting Greenland here.

View and download an OMG poster/infographic here.

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: GREENLAND, OCEANS, MELTING, GREENLAND, OMG

• 

  ABOUT THE AUTHOR

  Laura Faye Tenenbaum, Science Communicator

  Laura Faye Tenenbaum is a science communicator at NASA's Jet Propulsion Laboratory, teaches oceanography at Glendale Community College and writes the "Earth Right Now" blog for NASA's Global Climate Change website.

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

• 

  ABOUT THE AUTHOR

  Laura Faye Tenenbaum, Science Communicator

  Laura Faye Tenenbaum is a science communicator at NASA's Jet Propulsion Laboratory, teaches oceanography at Glendale Community College and writes the "Earth Right Now" blog for NASA's Global Climate Change website.