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By NASA
4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
The Permafrost Tunnel north of Fairbanks, Alaska, was dug in the 1960s and is run by the U.S. Army’s Cold Regions Research and Engineering Laboratory. It is the site of much research into permafrost — ground that stays frozen throughout the year, for multiple years.NASA/Kate Ramsayer Earth’s far northern reaches have locked carbon underground for millennia. New research paints a picture of a landscape in change.
A new study, co-authored by NASA scientists, details where and how greenhouse gases are escaping from the Earth’s vast northern permafrost region as the Arctic warms. The frozen soils encircling the Arctic from Alaska to Canada to Siberia store twice as much carbon as currently resides in the atmosphere — hundreds of billions of tons — and most of it has been buried for centuries.
An international team, led by researchers at Stockholm University, found that from 2000 to 2020, carbon dioxide uptake by the land was largely offset by emissions from it. Overall, they concluded that the region has been a net contributor to global warming in recent decades in large part because of another greenhouse gas, methane, that is shorter-lived but traps significantly more heat per molecule than carbon dioxide.
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Greenhouse gases shroud the globe in this animation showing data from 2021. Carbon dioxide is shown in orange; methane is shown in purple. Methane traps heat 28 times more effectively than carbon dioxide over a 100-year timescale. Wetlands are a significant source of such emissions.NASA’s Scientific Visualization Studio The findings reveal a landscape in flux, said Abhishek Chatterjee, a co-author and scientist at NASA’s Jet Propulsion Laboratory in Southern California. “We know that the permafrost region has captured and stored carbon for tens of thousands of years,” he said. “But what we are finding now is that climate-driven changes are tipping the balance toward permafrost being a net source of greenhouse gas emissions.”
Carbon Stockpile
Permafrost is ground that has been permanently frozen for anywhere from two years to hundreds of thousands of years. A core of it reveals thick layers of icy soils enriched with dead plant and animal matter that can be dated using radiocarbon and other techniques. When permafrost thaws and decomposes, microbes feed on this organic carbon, releasing some of it as greenhouse gases.
Unlocking a fraction of the carbon stored in permafrost could further fuel climate change. Temperatures in the Arctic are already warming two to four times faster than the global average, and scientists are learning how thawing permafrost is shifting the region from being a net sink for greenhouse gases to becoming a net source of warming.
They’ve tracked emissions using ground-based instruments, aircraft, and satellites. One such campaign, NASA’s Arctic-Boreal Vulnerability Experiment (ABoVE), is focused on Alaska and western Canada. Yet locating and measuring emissions across the far northern fringes of Earth remains challenging. One obstacle is the vast scale and diversity of the environment, composed of evergreen forests, sprawling tundra, and waterways.
This map, based on data provided by the National Snow and Ice Data Center, shows the extent of Arctic permafrost. The amount of permafrost underlying the surface ranges from continuous — in the coldest areas — to more isolated and sporadic patches.NASA Earth Observatory Cracks in the Sink
The new study was undertaken as part of the Global Carbon Project’s RECCAP-2 effort, which brings together different science teams, tools, and datasets to assess regional carbon balances every few years. The authors followed the trail of three greenhouse gases — carbon dioxide, methane, and nitrous oxide — across 7 million square miles (18 million square kilometers) of permafrost terrain from 2000 to 2020.
Researchers found the region, especially the forests, took up a fraction more carbon dioxide than it released. This uptake was largely offset by carbon dioxide emitted from lakes and rivers, as well as from fires that burned both forest and tundra.
They also found that the region’s lakes and wetlands were strong sources of methane during those two decades. Their waterlogged soils are low in oxygen while containing large volumes of dead vegetation and animal matter — ripe conditions for hungry microbes. Compared to carbon dioxide, methane can drive significant climate warming in short timescales before breaking down relatively quickly. Methane’s lifespan in the atmosphere is about 10 years, whereas carbon dioxide can last hundreds of years.
The findings suggest the net change in greenhouse gases helped warm the planet over the 20-year period. But over a 100-year period, emissions and absorptions would mostly cancel each other out. In other words, the region teeters from carbon source to weak sink. The authors noted that events such as extreme wildfires and heat waves are major sources of uncertainty when projecting into the future.
Bottom Up, Top Down
The scientists used two main strategies to tally greenhouse gas emissions from the region. “Bottom-up” methods estimate emissions from ground- and air-based measurements and ecosystem models. Top-down methods use atmospheric measurements taken directly from satellite sensors, including those on NASA’s Orbiting Carbon Observatory-2 (OCO-2) and JAXA’s (Japan Aerospace Exploration Agency)Greenhouse Gases Observing Satellite.
Regarding near-term, 20-year, global warming potential, both scientific approaches aligned on the big picture but differed in magnitude: The bottom-up calculations indicated significantly more warming.
“This study is one of the first where we are able to integrate different methods and datasets to put together this very comprehensive greenhouse gas budget into one report,” Chatterjee said. “It reveals a very complex picture.”
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Written by Sally Younger
2024-147
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Last Updated Oct 29, 2024 Related Terms
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The commander of Space Forces Indo-Pacific discussed the importance of working with regional allies in order to deter adversaries and maintain a rules-based international order, Oct. 22.
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By USH
A strange image has been circulating across social media in Thailand, showing a large, dark pillar-like structure mysteriously appearing in the sky over Ubon Ratchathani. According to the photographer, the picture was taken on Sunday, October 20, 2024, while they were trying to capture the "beautiful, colorful sky.
This peculiar sighting isn't entirely unprecedented. Similar strange phenomena have been reported before. On October 7, 2015, a mysterious "floating city" with skyscrapers appeared in the clouds over Foshan, Guangdong province in China. Again, on March 18, 2016, ghostly buildings were seen above the sea along the port of Dalian, in Liaoning Province, China, lingering in the sky for several minutes.
Most recently, on September 11, 2020, an eerie image resembling the Hogwarts School from Harry Potter was spotted hovering over modern buildings in Jinan, Shandong Province. On July 14, 2022, a bizarre occurrence was also witnessed by residents in Haikou, Hainan, where a mysterious floating city appeared in the sky.
Scientists suggest that these events are most likely optical illusions, with mirages being the leading theory. Mirages occur when light rays bend, causing distant objects or parts of the sky to appear displaced. One specific type, known as a Fata Morgana, can create towering, distorted images of distant objects, contributing to these surreal sights.
Although the sightings between 2015 and 2022 were witnessed by many, the photographer in Thailand later realized that the mysterious pillar hadn't been visible to the naked eye at the time. This discovery has led some to speculate that the phenomenon might have been caused by a Project Blue Beam test, holographic technology, or even a temporary vortex connected to a parallel universe.
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By NASA
A mentor of research scientist Meloë Kacenelenbogen once shared a sentiment from French author André Gide: “You cannot discover new oceans unless you have the courage to lose sight of the shore.” Kacenelenbogen pushes beyond her comfort zone to explore the unknown.
Name: Meloë S. Kacenelenbogen
Formal Job Classification: Research scientist
Organization: Climate and Radiation Laboratory, Science Directorate (Code 613)
Dr. Meloë S. Kacenelenbogen is a research scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md. She studies the impact of aerosols on air quality and the Earth’s climate.Photo courtesy of Meloë Kacenelenbogen What do you do and what is most interesting about your role here at Goddard?
I study the impact of aerosols — suspended particles from, for example, wildfire smoke, desert dust, urban pollution, and volcanic eruptions — on air quality and the Earth’s climate. I use space, air, and ground-based observations, as well as models.
Why did you become a scientist? What is your educational background?
I never made a deliberate choice to become a scientist. I started with very little confidence as a child and then built up my confidence by achieving things I thought I could not do. I chose the hardest fields to work on along the way. Science looked hard and so did fluid mechanics, remote sensing, and atmospheric physics. I have failed many times, but I always learn something and move on. I do get scared and maybe even paralyzed for a day or two, but I never let fear or failure immobilize me for long.
I was born in Maryland, but my family moved to France when I was young, so I am fluent in French. I have a bachelor’s and master’s degree in mechanical engineering, and physical methods in remote sensing from the Université Pierre et Marie Curie (Paris VI, Jussieu). In 2008, I got a Ph.D. in atmospheric physics for applying satellite remote sensing to air quality at the Université des Sciences et Technologies de Lille (USTL), France.
What are some of your career highlights?
After my Ph.D., I worked for the Atmospheric Lidar Group at the University of Maryland, Baltimore County (UMBC), on spaceborne and ground-based lidars. In 2009, I got a NASA Post-doctoral Program (NPP) fellowship at the agency’s Ames Research Center in California’s Silicon Valley, where I worked for 13 years on space-based, aircraft-based, and ground-based atmospheric aerosol vertical distribution and aerosol typing.
In 2022, I came to work at the Climate and Radiation Lab at Goddard.
What is most interesting about aerosols?
Aerosols are very topical because they have a huge impact on the air we breathe and our Earth’s climate. The smaller the aerosol, the deeper it can get into our lungs. Among other sources, aerosols can come from cars, factories, or wildfires. We all know that wildfires are becoming bigger and more frequent. They are expected to happen even more frequently in the future due to climate change. Both when I was living in California and here in Maryland, I have experienced first-hand choking from the wildfire smoke. I will always remember how apocalyptic it felt back in the summer of 2020 in California when wildfire smoke was paired with COVID confinement, and the sky turned Mars-like orange.
Please tell us about your involvement with the Atmosphere Observing System (AOS)?
I am incredibly lucky to be able to contribute to the next generation of NASA’s satellites. I am working on AOS, which will observe aerosols, clouds, convention, and precipitation in the Earth’s atmosphere. I am part of the team that is helping design several instruments and algorithms.
My role is to connect this spaceborne observing system to all our other space, ground, and air-based measurements at the time of launch. We are making a mesh of observations to address the science questions, run the algorithms, and validate the spaceborne measurements. I am constantly pushed to expand my horizon and my own knowledge.
Why do you enjoy always challenging yourself intellectually?
I started that way. I had no confidence, so I felt that the only way I could build my confidence was to try doing things that scared me. I may sometimes be a little scared, but I am never bored.
What did you learn from your mentors?
A few years ago, a mentor shared a quote from André Gide with me that encapsulates what we are talking about: “You cannot discover new oceans unless you have the courage to lose sight of the shore.” In other words, it is OK, maybe preferable, to be out of my comfort zone to explore the unknown as scary as it may be.
Along the way, it has been extremely important for me to deliberately choose mentors. To me, a good mentor has earned the respect of all who have worked with them, is uplifting, reassuring, and gives me the invaluable guidance and support that I need. I deliberately try to surround myself with the right people. I have been very, very fortunate to find incredible people to encourage me.
As a mentor, what do you advise?
I tell them to deliberately choose their mentors. I also tell them that it is OK to be uncomfortable. Being uncomfortable is the nature of our field. To do great things, we often need to be uncomfortable.
Why do you enjoy working on a team?
I love working on teams, I love to feed off the positive energy of a team whether I lead it or am part of it. In my field, teamwork with a positive energy is incredibly satisfying. Everybody feeds off everybody’s energy, we go further, are stronger, and achieve more. This may not happen often, but when it does it makes it all worth it.
What are the happiest moments in your career?
I am always happiest when the team publishes a paper and all our efforts, are encapsulated in that one well-wrapped and satisfying peer-reviewed paper that is then accessible to everyone online. Every paper we publish feels, to me, the same as a Ph.D. in terms of the work, pain, energy, and then, finally, satisfaction involved.
What do you hope to achieve in your career?
I want to have been a major contributor to the mission by the time the AOS satellites launch.
What do you do for fun?
I do mixed martial arts. I love the ocean, diving, and sailing. I also love going to art galleries, especially to see impressionist paintings to reconnect with my Parisian past.
Meloë Kacenelenbogen once shared a sentiment from French author André Gide: “You cannot discover new oceans unless you have the courage to lose sight of the shore.”Photo courtesy of Meloë Kacenelenbogen Who is your favorite author?
I love Zweig, Kafka, Dostoyevsky, Saint-Exupéry, and Kessel. The latter two wrote a lot about aviators in the early 1900s back in the days when it was new and very dangerous. Those pilots, like Mermoz, were my heroes growing up.
Who would you like to thank?
I would like to thank my family for being my rock.
What are your guiding principles?
To paraphrase Dostoevsky, everyone is responsible to all men for all men and for everything. I have a strong sense of purpose, pride, justice, and honor. This is how I try to live my life for better or for worse.
By Elizabeth M. Jarrell
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Conversations With Goddard is a collection of Q&A profiles highlighting the breadth and depth of NASA’s Goddard Space Flight Center’s talented and diverse workforce. The Conversations have been published twice a month on average since May 2011. Read past editions on Goddard’s “Our People” webpage.
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Last Updated Oct 22, 2024 EditorMadison OlsonContactRob Garnerrob.garner@nasa.govLocationGoddard Space Flight Center Related Terms
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