I looked out the window of NASA’s modified G-III aircraft across the expanse. I knew what I would see. I knew it would look like white pillow-y ripples going on and on and on, way farther than anyone could see, like a vast field of white sand dunes stretching away into the distance.
The Oceans Melting Greenland (OMG) aircraft was flying across the entire top half of Greenland from the northwest coast to the northeast coast to make the day’s first science measurements. And the first science flight line was all the way across the Greenland Ice Sheet, across 620 miles (1,000 kilometers) of ice that’s up to 2 miles thick and hundreds of thousands of years old. And although I’d flown in Greenland a bunch of times before, I’d only ever flown over the coastal areas, where glaciers around the ice sheet’s edges carve their way through the Greenland terrain, to cut out deep, narrow fjords over centuries’ time.
Everything here is vast and expansive: the size, the views, the enormous quantity of ice.
Two days before, I’d trekked up to the ice sheet with a few members of the OMG team. We stood in the insanely cold, dry, biting air (Greenland is one of the least humid areas on planet Earth, with the cleanest, clearest air) and gazed into the incomprehensible distance. It was easy to use a snow boot to scrape the 2 inches or so of fine, dry, powdery snow away from the ice sheet to uncover the hard, greenish blue ice.
On the edge of the ice sheet, a slice of ancient ice layers was exposed like a glistening wall, and we’d walked past it on the way up to the top of the sheet. The ice wall was so vertical and so sheer, the snow that hid the other parts of the edge had fallen away, and we could see its smooth surface shining like a gem: striped blue and green. That ice is hundreds of thousands of years old, made from snow that fell year after year after year, eventually becoming compressed and preserved in this cold, dry desert environment.
Standing on top of the ice sheet, I imagined it under my feet, going down and down and down for a mile or more.
A mile—or more—of ice.
Everything here is vast and expansive: the size, the views, the enormous quantity of ice. Flying over them, the glaciers look like hundreds of broad frozen rivers, each one up to a few miles across, each one channeling its way from the interior of the landmass toward the sea over thousands of years. Each glacier carved out a fjord through the rock and out to sea in the same way a river erodes its channel, except it’s so much bigger, so much slower and the erosional power of the ice is so much more intense. From up here, the glacier’s impossibly slow creep seems frozen in both space and time. But the glaciers are moving. Stress fractures or crevasses, which are easy-to-observe evidence of glacier movement, form as the glaciers slope downhill toward the sea. And of course, we also have scientific measurements. Detailed satellite images show that the terminal edges of many glaciers such as Jakobshavn have receded by as much as 0.4 miles (600 meters) per year in recent times. Scientists also have time-lapse footage of seaward glacier flow.
But having evidence of glacier flow, and even glacier recession, is only part of the story. As a warmer atmosphere and a warmer ocean around the coastline continue to melt the massive amount of ice that covers Greenland, the ice ends up flowing into the ocean, which causes sea level rise worldwide.
As we flew over, the GLISTIN-A instrument received data from a 12-kilometer swath of whatever is below and off to the sides of it, in this case glaciers. Using these data, we can measure, with great precision, the height of each glacier we fly over. See, when the end of an individual glacier melts and calves into the ocean, the whole glacier speeds up and flows even faster downhill toward the ocean because there’s less friction against the sides and bottom to slow it down. The faster it moves, the more it stretches — like pulled taffy — and when a glacier is all stretched out, its elevation is lower. And because OMG will fly the same science lines along the same coastal glaciers every year for five years in a row, we’ll be able to find out how much elevation each glacier has lost, how fast it’s flowing into the ocean and how much ice has been lost.
They sure appear stable, still, enduring. But they’re not. They’re melting.
They sure appear stable, still, enduring. But they’re not. They’re melting.
And northern Greenland, along with the rest of the higher latitudes in the Northern Hemisphere, is experiencing some of the most intense impacts of global climate change right now, today.
Thank you for reading.
The world seems smaller to Steve Wofsy than it used to. He’s the lead scientist for NASA’s Atmospheric Tomography (ATom) mission, an airborne mission to survey the gases on the world’s atmosphere that has just finished up a round-the-world flight.
Wofsy is tall and lanky and at 70 is still an active professor and researcher at Harvard University. He began thinking about a mission like ATom 30 years ago to take a slice of the atmosphere from pole to pole to see what gases were there both naturally and from pollution, how they behaved, and how they collectively affected Earth’s climate. Building on years of research and airborne field work, including a mission Wofsy led to sample the air above the Pacific from pole to pole, ATom brings more than 22 instruments and a hundred scientists from universities and agencies around the world to begin to close the loop on some outstanding questions.
Of particular interest are three greenhouse agents: ozone that occurs in the lower atmosphere as a result of human pollution, methane that also primarily comes from human activities, and black carbon, tiny black particles that come from fires that absorb heat and interact with clouds. These three make up the number two, three, and four most important human-emitted greenhouse agents after carbon dioxide, which is also being measured.
"Together they account for almost as much warming of the surface as carbon dioxide," Wofsy explained to me.
What sets them apart is how long they stay in the atmosphere. Unlike carbon dioxide which persists for over a century before being removed from the atmosphere, ozone in the lower atmosphere reacts with other gases within a year and methane sticks around for more than a decade. This means that reducing human emissions of these two gases could make a difference in the greenhouse effect in our lifetimes. But because they're both reactive, their concentration in the atmosphere can vary a lot from place to place. Hence the importance of the up-close, around-the-world measurements made by the instruments on the ATom mission to get a handle on how much is there now and how it may change in the future.
The sky was overcast when we went out to see the plane. NASA’s DC-8 looks like an older-model commercial aircraft from the outside (which it was), but from the inside its all science. Instead of rows of seats, large metal frame structures – racks to hold the instruments and computers – dominate the view with only a pair of seats next to each one. A few scientists were onboard fine-tuning their instruments or resupplying gases and filters.
Instead of hunting for particular gases in particular pollution-prone regions, Wofsy and the science team want to measure everything they can, not just the greenhouse gases — from soot and remnant gases of fires burned on land, sulfur dioxide from volcanoes and coal-burning power plants, and industrial air pollutants. They are flying near some major land masses, but more importantly, they’re flying high over the ocean, the remotest and supposedly cleanest parts of the atmosphere to see how far humanity’s fingerprints on the air have traveled.
The answer: pretty far. This February, above the Arctic, they saw traces of Asian pollution. Above both the Pacific and Atlantic, they saw traces of African fires.
ATom left New Zealand for the southern tip of Chile and then completed the circuit flying north over the middle of the Atlantic Ocean. They arrived back in California at the end of February, finishing their second of four deployments, one to take place in each season. The mission takes to the air next this October.
Most people I meet don’t spend much time thinking about the polar regions on planet Earth; the poles just seem too far away. I mean, Antarctica, really? Only extreme explorers and a few scientists spend time thinking about those frozen places. Most of us live in areas with moderate temperatures, fantasize about tropical vacations and have barely checked out what the far reaches of our planet look like on a map. And even maps neglect the far north and south by stretching them so much that many people have no real idea what the ends of the Earth look like.
I became interested, and then obsessed, with Earth’s icy regions during a particularly hot Los Angeles summer a couple of years ago when I created NASA’s Global Ice Viewer. Sitting in my office scouring NASA vaults for the most intriguing views of our planet’s ice was like going on a wild interstellar journey to someplace beyond my wildest imagination; it changed my view of our planet forever.
These days, I frequently give public speeches and show audiences what the Arctic and Antarctic look like from space. It surprises me how little people know about these portions of our world. Perhaps their biggest misunderstanding is that the Arctic and Antarctic are similar. You know, one’s in the north and the other is in the south; but other than that, they’re the same, right? No, this couldn’t be more wrong. These polar opposites are literally polar opposites.
For starters, the Arctic is an ocean surrounded by land: Eurasia, Greenland, Canada and the United States. It’s only about 5.5 million square miles, which is five times smaller than the Atlantic and 11 times smaller than the Pacific. Antarctica, on the other hand, is a continent surrounded by the entire Southern Ocean.
In the winter, the Southern Ocean around the Antarctic continent also becomes covered with sea ice. But every summer most of this sea ice melts. That’s because the ice edge around Antarctica is exposed to open ocean, and every direction you go is north. So, during the summer, most of the sea ice moves north and melts away. This means that very little Antarctic sea ice is more than two years old. But Arctic sea ice is trapped inside the enclosed ocean. This means that during the summer months, even though much of the sea ice melts, it doesn’t melt completely.
More than opposites
Is this complicated enough? If you’ve been reading closely, by now you’ll know that those two types of sea ice are probably super duper different because, yup, you guessed it: The two poles are much more than opposites.
Since 1979, NASA satellite measurements have observed an overall decline in Arctic sea ice due to climate change. Climate change warms the air as well as the ocean water, and melts the sea ice. Climate change has also caused some of the Antarctic ice shelves (which are part of Antarctica’s fresh water ice sheet that extends into the ocean, surrounding the continent) to collapse.
But the story of the sea ice floating around Antarctica in the Southern Ocean is even more complex. This sea ice is not just frozen seawater, like the Arctic sea ice. There’s more snow in the Southern Ocean — that ice is made of sea ice, covered by snow ice (frozen sea water from surface flooding), covered by snow. It’s a snowman ice cream sandwich! And the strong winds down there easily blow this mixture across the ocean surface, making Antarctic sea ice extent highly variable. This year, satellites observed that Antarctic sea ice extent set a record low, dropping to its lowest extent ever recorded.
The fact that our Earth is a crazy complicated place makes it such a challenge to understand, but that same truth also makes it amazing. Earth is never boring, which is why we keep paying attention to and never tire of learning more about it.
Test how much you know and learn more about Earth’s frozen places with these fun quizzes:
As always, I welcome your comments.
This post is an updated version of a previous blog post.
When viewed from space, our planet is wondrous in its diversity, variety and beauty. And as we’ve noted many times in this blog, images of Earth sometimes look like art and often inspire creativity.
One of our all-time favorite stories about the view of our amazing planet from space comes from one of our sister websites, Earth Observatory. Thank you, Adam Voiland, for this fun piece that depicts all 26 letters of the alphabet from satellite images and astronaut photos. You’ve done a great job of showcasing the vast range of landscapes, topography and geology of planet Earth.
I hope you enjoy this piece as much as we do.
At NASA, I spend a large portion of my work day looking at satellite images of Earth, an amazingly glorious expanded view. Go to our Beautiful Earth, Earth as Art, and Images of Change galleries (the latter is also available as an iPad app) and see for yourself. While you’re checking out our amazing images, you’ll probably also notice something that I see almost every day: Our planet is so beautiful, the images actually look like works of art.
The Earth is our home. And looking at places on the far side of our planet can give you a sense of intimacy with the whole world. That’s how my conversation with aerial photographer Timo Lieber began.
“Photography and science are a quite powerful combination,” Timo Lieber told me. We were discussing his project, THAW, a series of eleven large-scale aerial photographic images that capture the Greenland polar ice cap melting. “The extent of the melting is increasing and the net loss is worsening every single year,” he explained. “I want to put images right in front of people that show that global warming is, in fact, happening.”
“Greenland is a sensational color palette. You rarely find a landscape that’s so pristine as the Arctic.”
As a photographer, Lieber has wanted to create a body of work that explores in pictures some of the changes that are taking place in the Arctic, to translate the melting ice sheet into beautiful photographs and “to catch the viewers’ attention so that ultimately the viewer gets interested in the subject via the image.”
He teamed up with scientists from Scott Polar Research Institute at the University of Cambridge, who have been conducting research in Greenland for a number of years, and they pointed him in the direction of a series of surface melt lakes that have been increasing in size. Lieber decided to document the lakes in this exhibition of photographs.
Even though Lieber used satellite images to research the location of the lakes, once he was on the ice cap, he found “blue lakes for as far as you can see.” Because the lakes are connected, with one flowing into the other until it drops off into a moulin, he was able to follow one lake to another. “There are lakes and water literally everywhere,” he told me.
Yes, Greenland is beautiful—the ice, the lakes, the crevasses and the blues that go on and on and on. It’s a true work of art, and according to Lieber, “It’s the perfect canvas for my type of photography.”
Thank you for reading.
“This year we’re gonna bring it!” Oceans Melting Greenland (OMG) Principal Investigator Josh Willis told me excitedly. “It’s the beginning of year two of this five-year airborne mission, which means that by comparing data from the first and second years, we’ll be able to observe changes in Greenland’s glaciers and coastal ocean water for the first time.” Glaciers around Greenland’s jagged coastline have been melting into the ocean and causing increased sea level rise, so measuring the amount of ice mass loss will help us understand the impact of these changes, Willis said. “Will we see 5 feet of sea level rise this century … or more?”
See, Earth’s ocean, more than the atmosphere, is responsible for creating a stable climate. And as global warming has increased the temperature of the ocean waters surrounding Greenland, that warmer ocean water is melting the ice sheet from around its edges. “Hey! The ocean is eating away at the ice sheet!” Willis often cries when explaining the mission. And Team OMG is measuring how much of that warm water could be increasing due to climate change.
Decoding the environment
I understand how Willis and Project Manager Steve Dinardo get excited about measuring sea level rise. Greenland’s ice melt is accelerating, which explains why NASA is paying attention to it. Plus, after a successful first year, the team is fully aware of the stark beauty of Greenland’s rugged landscape and seascape and the rewards of bonding as a team. Dinardo told me he was “ecstatic about the incredible progress Team OMG has made in the last twenty-two months.”
As scientists, decoding the natural world is our way of caring about the environment. We care about Greenland’s icy coastline, so we go there. We go there and observe. We go there and measure. For there is something undeniable about the sheer beauty of this planet, and any time you get to experience it is a moment to feel exuberant and alive. Plus, flying around with a great team in a modified NASA G-III aircraft ain’t too shabby either.After a successful first year, the team is fully aware of the stark beauty of Greenland’s rugged landscape and seascape and the rewards of bonding as a team.
But wait. Before I continue, there’s something you probably noticed: Willis said he named this Greenland observing expedition Oceans Melting Greenland, or OMG for short, because, hey, OMG is the exact response you might have when you find out what’s going on up there.
Parts of Greenland’s coastline are so remote, so difficult to access by boat, that they’d remain uncharted, especially under areas that are seasonally covered with ice. Imagine the edge of an unimaginably complicated winding coastline, that unknown place where ice meets water meets seafloor. Big chunks of remnant sea ice clog up the water, and the glacier has retreated so recently that the coastline is changing as fast as, or even faster than, we can study it.
The seawater around 400 meters deep is 3 to 4 degrees Celsius warmer than the water floating near the sea surface. And the sea floor bathymetry influences how much of that warm subsurface layer can reach far up into the fjords and melt the glaciers. So, to learn about the interface between where the bottom of the ice sheet reaches out over the seawater and down into the ocean, OMG began by mapping undersea canyons on the M/V Cape Race, a ship equipped with an echo sounder, which sailed right up the narrow fjords on the continental shelf surrounding Greenland to the places where the warmer Atlantic Ocean water meets the bottoms of the frozen, 0-degree glaciers. The crew had to snake in between floating icebergs and weave in and out of narrow fjords. The Cape Race used a multibeam echo sounder to map undersea canyons, where the warm seawater comes in contact with and melts the glaciers.
The next four years
In the spring of 2016, the Oceans Melting Greenland (OMG) team began surveying glacier elevation near the end of marine-terminating glaciers by precisely measuring the edges of the ice sheet on a glacier-by-glacier basis, using the Airborne Glacier and Land Ice Surface Topography Interferometer (GLISTIN-A), a radar instrument attached to the bottom of a modified NASA G-III aircraft. Data collected this spring and over the next four years can be compared with data collected in the spring of 2016 so we can determine how fast the glaciers are melting.
The investigation continued into last fall, with the team dropping more than 200 Aircraft eXpendable Conductivity Temperature Depth (AXCTD) probes that measured ocean temperature and salinity around Greenland, from the sea surface to the sea floor, through a hole in the bottom of the plane. “In most of these places,” Willis told me, “there’s been no temperature and salinity data collected. Ever.”As scientists, decoding the natural world is our way of caring about the environment.
The team will drop more ocean probes across the same locations to find out “how much ice melts when the water is this warm,” what the melt rate is, and how much that rate is increasing, because no one knows the melt rate yet.
Big picture project
“OMG is a big picture project,” Willis explained. ”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.”
As part of Team OMG, I also flew on NASA’s G-III into uncontrolled airspace to places where no other aircraft had flown before, into narrow and steep ice-covered fjords, winding in and out, up and down, over and through to observe and measure, like scientists do. I saw the brilliant white ice carve its way through steep brown valleys into open ocean water. I saw the glorious expanse of white upon deep blue going on and on and on below us as we flew just 5,000 feet above the winding coastline. It was extraordinary.
And if you just thought “OMG,” Willis would be proud.
Thanks for reading.
Leaves blown in by a strong wind lay scattered across the foyer of the building where I work. The skies are greyer, and the sun’s rays lay low in the late afternoon. The world is quietly exhaling.
In the stillness of winter solstice, that time of year when days are shorter and nights are longer, when the Earth’s Northern Hemisphere is as tilted away from the sun as it will ever be, I let the cold starkness surround me like a blanket.
In this moment, time seems to stand still, even as Earth continues its enduring revolution around our star. Even as seasons blend into each other year after year after year.
In this moment, I reach out to you, NASA reaches out to you. We are connected. Together we breathe, together we watch our world, together we look forward to the green shoots that make their way up through the soil. Because remember, after the longest of dark nights always comes the spring.
Find out more about equinoxes and solstices here.
My writing teacher and I said goodbye to each other. We cried together as I told her she would live on through my writing. She already knew. Because a dark night brings another sunrise, a winter brings another spring, and a goodbye brings another hello.
No one is truly alone; we rely on other people all the time. Teamwork, backing and support aren’t optional, they’re necessities.
The first writing assignment she gave me was to open my front door and describe the first plant I saw. Through this exercise, I learned how to observe the world and make detailed descriptions of those observations, while avoiding interpretations or judgmental words like “good,” or “nice,” or “pretty.” My writing became stronger when I told the story as it was, bringing along the reader and letting us both interpret the events together. For example, instead of telling you that I had a nice weekend, I learned to tell you that I sat near a fireplace with my puppy to my left and a friend on my right, drinking lemon, mint and honey (all right, there was a tiny bit of gin in there, too) and making travel plans. Then you, the reader, can make up your own mind about how my weekend was.
My writing teacher was a writer, a composer, a film producer. She was a true artist in every sense. And I’m sure you noticed the connection between the art of writing and the art of doing science, right? Science, including the type of satellite remote sensing at which NASA excels, is based on making detailed observations and allowing those observations to tell their story. NASA spacecraft give us images of glaciers, volcanoes, forests, large cities and sea ice, among other stories of a changing planet. And it’s up to us to see the details in those stories. When the images—the stories—have enough detail, we can interpret them and make meaning out of them.
When I think about how her life flows through me and out into the world, I also think about how we at NASA are part of a continuous stream of creative endeavors, of science, of aspirations achieved—each one built upon those who came before, and each one a step for the next ones to climb.
Thank you for reading.
Sigh. Sometimes life feels heavy.
Even as the holidays approach and we’re all supposed to be in a holiday spirit, supposed to be joyous. Sometimes we’re just not there.
But, as always, NASA gives me the opportunity to look at Earth from the highest perspective. From above, the world appears remote and untouched. There’s nothing but the timeless, immaculate and infinite beauty of our planet.
Together, you and I get to take this opportunity to share thankfulness for our Earth and everything pristine and beautiful about it.
Thank you for reading. I really mean it.
Earth, from the vantage point of space: Serene, breathtaking, magnificent. No matter how crazy busy your day is, no matter the level of stress, or chaos, or distraction, take a moment today—right now, in fact—to step back and feast on the great wonder of our home planet, Earth.