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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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Jane J. Lee / Andrew Wang
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0307 / 626-379-6874
jane.j.lee@jpl.nasa.gov / andrew.wang@jpl.nasa.gov
Written by Sally Younger
2024-147
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Last Updated Oct 29, 2024 Related Terms
Earth Carbon Cycle Climate Change Greenhouse Gases Jet Propulsion Laboratory Explore More
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By European Space Agency
Video: 00:00:23 From 7 until 13 October 2024, ESA/NASA’s SOHO spacecraft recorded Comet C/2023 A3 (Tsuchinshan–ATLAS), the second brightest comet it has ever seen. Meanwhile, large amounts of material were being spewed out by the Sun (covered in the centre), and planet Mercury is visible to the left.
The comet’s nucleus is clearly visible, surrounded by a dusty coma and trailing an impressively long tail. SOHO sees the large dust tail edge-on, curving in on itself as it is pushed outward by solar wind.
At the end of the video you can also see a rare phenomenon known as an ‘anti-tail’: a long, thin line that points towards the Sun. This tail is an optical illusion coming from SOHO getting an edge-on view of the larger cometary dust particles that accumulate in the comet’s orbital plane.
Comet C/2023 A3 was seen for the first time early last year. It most likely came from the distant Oort cloud, and the last time this comet flew through the inner Solar System (if ever) was at least 80 000 years ago.
The comet reached an estimated peak brightness just beyond –4 magnitude. (The more negative the visual magnitude value, the brighter the object.) Of the more than 5000 comets SOHO has seen flying past the Sun, only Comet C/2006 P1 (McNaught) was brighter, with a visual magnitude of –5.5.
SOHO’s location between the Sun and Earth gave it a front-row seat, but the same comet has been visible from Earth every evening since 12 October 2024. Throughout October, as the comet moves farther away from the Sun, it will gradually grow fainter and rise higher up in the western sky.
The week that SOHO watched Comet Tsuchinshan–ATLAS was also a wild one in terms of space weather. The Sun unleashed no less than 4 X-class flares (the highest intensity type of flare), 28 medium-intensity M-class flares, and 31 coronal mass ejections – the latter being visible as white clouds of material in the video. All this activity led to two geomagnetic storms on Earth, resulting in beautiful auroras lighting up the night sky.
SOHO, short for Solar and Heliospheric Observatory, is a joint ESA-NASA mission to study the Sun. For almost 29 years now, it has been watching the Sun itself as well as the much fainter light coming from the Sun’s outer atmosphere, called the solar corona. The data shown in this video were taken by the LASCO C3 coronagraph instrument.
Special thanks to Simeon Schmauß, who processed the raw data to create this impressive video. For comparison, here is a video of the comet with more standard data processing – the comet is so bright that it partially saturated SOHO’s sensor.
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By NASA
NASA/Matthew Dominick NASA astronaut Matthew Dominick captured this timelapse photo of Comet C/2023 A3 (Tsuchinshan-ATLAS) International Space Station as it orbited 272 miles above the South Pacific Ocean southeast of New Zealand just before sunrise on Sept. 28, 2024. At the time, the comet was about 44 million miles away from Earth.
Though the comet is very old, it was just discovered in 2023, when it approached the inner solar system on its highly elliptical orbit for the first time in documented human history. Beginning in mid-October 2024, Comet C/2023 A3 (Tsuchinshan-ATLAS) will become visible low in the west following sunset. If the comet’s tail is well-illuminated by sunlight, it could be visible to the unaided eye. Oct. 14-24 is the best time to observe, using binoculars or a small telescope.
The comet hails from the Oort Cloud, which scientists think is a giant spherical shell surrounding our solar system. It is like a big, thick-walled bubble made of icy pieces of space debris the sizes of mountains and sometimes larger. The Oort Cloud lies far beyond Pluto and the most distant edges of the Kuiper Belt and may contain billions, or even trillions, of objects.
Image Credit: NASA/Matthew Dominick
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By NASA
2 min read
ESA/NASA’s SOHO Spies Bright Comet Making Debut in Evening Sky
The tail of comet C/2023 A3 Tsuchinshan-ATLAS spanned the view of the Solar and Heliospheric Observatory (SOHO) on Oct. 10, 2024. ESA/NASA The ESA (European Space Agency) and NASA Solar and Heliospheric Observatory (SOHO) has captured images of the second-brightest comet to ever pass through its field of view during the spacecraft’s nearly 29-year career.
The bright comet is C/2023 A3 Tsuchinshan-ATLAS, which has been garnering a lot of attention from skywatchers recently, displaying a long, dusty tail in pre-dawn skies throughout late September and early October. (Comet McNaught, viewed in 2007, holds the record as the brightest comet SOHO has seen.)
Between Oct. 7 and 11, the comet blazed through the view of SOHO’s LASCO (Large Angle and Spectrometric Coronagraph Experiment) instrument, which uses a disk to block out the bright light of the Sun so it’s easier to see details and objects near the Sun. This image, taken by SOHO on Oct. 10, 2024, shows the comet and its bright tail streaming from the upper left to the right. Mercury appears as a bright dot on the left.
After crossing through SOHO’s field of view, the comet will begin putting on an evening show for skywatchers around the world just after sunset starting Saturday, Oct. 12. Each day throughout October, the comet will gradually rise higher and higher in the western sky as it moves farther away from the Sun. But as it does, it will become fainter and fainter. Eagle-eyed skywatchers may be able to spot it with the naked eye for a few days, but after that, observers will likely need binoculars or a telescope to see it as it grows fainter.
Even if you are unable to spot this comet yourself, you can help SOHO search for others. Scientists and members of the general public have discovered more than 5,000 comets in SOHO imagery, and you can help find even more by visiting the Sungrazer Project.
By Vanessa Thomas
NASA’s Goddard Space Flight Center, Greenbelt, Md.
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Last Updated Oct 11, 2024 Related Terms
Comets Goddard Space Flight Center Heliophysics Heliophysics Division Skywatching SOHO (Solar and Heliospheric Observatory) The Sun The Sun & Solar Physics Explore More
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By NASA
5 min read
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A recent NASA-funded study quantified higher levels of fine particulate air pollution near Southern California warehouses, a result of emissions from diesel trucks that transport goods to and from such facilities. Inhalation of these tiny particles can cause serious health problems.Adobe Stock/Matt Gush Satellite-based data offers a broad view of particulate air pollution patterns across a major West Coast e-commerce hub.
As goods of all shapes and sizes journey from factory to doorstep, chances are they’ve stopped at a warehouse along the way — likely several of them. The sprawling structures are waypoints in the logistics networks that make e-commerce possible. Yet the convenience comes with tradeoffs, as illustrated in a recent NASA-funded study.
Published in the journal GeoHealth, the research analyzes patterns of particulate pollution in Southern California and found that ZIP codes with more or larger warehouses had higher levels of contaminants over time than those with fewer or smaller warehouses. Researchers focused on particulate pollution, choosing Southern California because it is a major distribution hub for goods: Its ports handle 40% of cargo containers entering the country.
The buildings themselves are not the major particulate sources. Rather, it’s the diesel trucks that pick up and drop off goods, emitting exhaust containing toxic particles called PM2.5. At 2.5 micrometers or less, these pollutants can be inhaled into the lungs and absorbed into the bloodstream. Although atmospheric concentrations are typically so small they’re measured in millionths of a gram per cubic meter, the authors caution that there’s no safe exposure level for PM2.5.
“Any increase in concentration causes some health damage,” said co-author Yang Liu, an environmental health researcher at Emory University in Atlanta. “But if you can curb pollution, there will be a measurable health benefit.”
A data visualization shows the average concentration of PM2.5 particulate pollution in the Los Angeles region from 2000 to 2018, along with the locations of nearly 11,000 warehouses. Darker red indicates higher concentration of these toxic particles; small black circles represent warehouse locations.NASA Earth Observatory Growing Air Quality Research
Particulate pollution has been linked to respiratory and cardiovascular diseases, some cancers, and adverse birth outcomes, including premature birth and low infant birth weight.
The new study is part of a broader effort funded by the NASA Health and Air Quality Applied Sciences Team to use satellite data to understand how air pollution disproportionately affects underserved communities.
As the e-commerce boom of recent decades has spurred warehouse construction, pollution in nearby neighborhoods has become a growing area for research. New structures have often sprouted on relatively inexpensive land, which tends to be home to low-income or minority populations who bear the brunt of the poor air quality, Liu said.
Another recent NASA-funded study analyzed satellite-derived nitrogen dioxide (NO2) measurements around 150,000 United States warehouses. It found that concentrations of the gas, which is a diesel byproduct and respiratory irritant, were about 20% higher near warehouses.
Distribution Hub
For the GeoHealth paper, scientists drew on previously generated datasets of PM2.5 from 2000 to 2018 and elemental carbon, a type of PM2.5 in diesel emissions, from 2000 to 2019. The data came from models based on satellite observations, including some from NASA’s MODIS (Moderate Resolution Imaging Spectroradiometer) and ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) instruments.
The researchers also mined a real estate database for the square footage as well as the number of loading docks and parking spaces at nearly 11,000 warehouses across portions of Los Angeles, Riverside, and San Bernardino counties, and all of Orange County.
They found that warehouse capacity correlated with pollution. ZIP codes in the 75th percentile of warehouse square footage had 0.16 micrograms per cubic meter more PM2.5 and 0.021 micrograms per cubic meter more elemental carbon than those in the 25th percentile.
Similarly, ZIP codes in the 75th percentile of number of loading docks had 0.10 micrograms per cubic meter more PM2.5 and 0.014 micrograms per cubic meter more elemental carbon than those in the 25th percentile. And ZIP codes in the 75th percentile of truck parking spaces had 0.21 micrograms per cubic meter more PM2.5 and 0.021 micrograms per cubic meter more elemental carbon than those in the 25th percentile.
“We found that warehouses are associated with PM2.5 and elemental carbon,” said lead author Binyu Yang, an Emory environmental health doctoral student.
Although particulate pollution fell from 2000 to 2019 due to stricter emissions standards, the concentrations in ZIP codes with warehouses remained consistently higher than for other areas.
Researchers also found that the gaps widened in the holiday shopping season, up to 4 micrograms per cubic meter — “a significant difference,” Liu said.
Satellites Provide Big Picture
Satellite observations, the researchers said, were essential because they provided a continuous map of pollution, including pockets not covered by ground-based instruments.
It’s the same motivation behind NASA’s TEMPO (Tropospheric Emissions: Monitoring of Pollution) mission, which launched in April 2023 and measures air pollution hourly during daylight over North America. The release of TEMPO’s first maps showed higher concentrations of NO2 around cities and highways.
Meanwhile, NASA and the Italian Space Agency are collaborating to launch the MAIA (Multi-Angle Imager for Aerosols) in 2026. It will be the first NASA satellite mission whose primary goal is to study health effects of particulate pollution while distinguishing between PM2.5 types.
“This mission will help air quality managers and policymakers conceive more targeted pollution strategies,” said Sina Hasheminassab, a co-author and science systems engineer at NASA’s Jet Propulsion Laboratory in Southern California. Hasheminassab, like Liu, is a member of the MAIA science team.
News Media Contacts
Andrew Wang / Jane J. Lee
Jet Propulsion Laboratory, Pasadena, Calif.
626-379-6874 / 818-354-0307
andrew.wang@jpl.nasa.gov / jane.j.lee@jpl.nasa.gov
2024-134
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Last Updated Oct 09, 2024 Related Terms
Earth Earth Science Earth Science Division Jet Propulsion Laboratory MAIA (Multi-Angle Imager for Aerosols) Explore More
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