New from JWST: an exoplanet atmosphere as never seen before

Peer-Reviewed Publication

HARVARD-SMITHSONIAN CENTER FOR ASTROPHYSICS

 

IMAGE: NEW OBSERVATIONS OF WASP-39B WITH THE JWST HAVE PROVIDED A CLEARER PICTURE OF THE EXOPLANET, SHOWING THE PRESENCE OF SODIUM, POTASSIUM, WATER, CARBON DIOXIDE, CARBON MONOXIDE AND SULFUR DIOXIDE IN THE PLANET'S ATMOSPHERE. THIS ARTIST'S ILLUSTRATION ALSO DISPLAYS NEWLY DETECTED PATCHES OF CLOUDS SCATTERED ACROSS THE PLANET. view more 

CREDIT: MELISSA WEISS/CENTER FOR ASTROPHYSICS | HARVARD & SMITHSONIAN

Cambridge, Mass. – The JWST just scored another first: a detailed molecular and chemical portrait of a distant world’s skies.

The telescope’s array of highly sensitive instruments was trained on the atmosphere of a “hot Saturn” — a planet about as massive as Saturn orbiting a star some 700 light-years away — known as WASP-39 b. While JWST and other space telescopes, including Hubble and Spitzer, previously have revealed isolated ingredients of this broiling planet’s atmosphere, the new readings provide a full menu of atoms, molecules, and even signs of active chemistry and clouds.

"The clarity of the signals from a number of different molecules in the data is remarkable,” says  Mercedes López-Morales, an astronomer at the Center for Astrophysics | Harvard & Smithsonian and one of the scientists who contributed to the new results. 

“We had predicted that we were going to see many of those signals, but still, when I first saw the data, I was in awe,” López-Morales adds.

The latest data also give a hint of how these clouds in exoplanets might look up close: broken up rather than a single, uniform blanket over the planet.

The findings bode well for the capability of JWST to conduct the broad range of investigations on exoplanets — planets around other stars — scientists hoped for. That includes probing the atmospheres of smaller, rocky planets like those in the TRAPPIST-1 system.

“We observed the exoplanet with multiple instruments that, together, provide a broad swath of the infrared spectrum and a panoply of chemical fingerprints inaccessible until JWST,” said Natalie Batalha, an astronomer at the University of California, Santa Cruz, who contributed to and helped coordinate the new research. “Data like these are a game changer.”

The suite of discoveries is detailed in a set of five newly submitted scientific papers, available on the preprint website arXiv. Among the unprecedented revelations is the first detection in an exoplanet atmosphere of sulfur dioxide, a molecule produced from chemical reactions triggered by high-energy light from the planet’s parent star. On Earth, the protective ozone layer in the upper atmosphere is created in a similar way.

“The surprising detection of sulfur dioxide finally confirms that photochemistry shapes the climate of ‘hot Saturns,’” says Diana Powell, a NASA Hubble fellow, astronomer at the Center for Astrophysics and core member of the team that made the sulfur dioxide discovery. “Earth’s climate is also shaped by photochemistry, so our planet has more in common with ‘hot Saturns’ than we previously knew!”

Jea Adams a graduate student at Harvard and researcher at the Center for Astrophysics analyzed the data that confirmed the sulfur dioxide signal. 

“As an early career researcher in the field of exoplanet atmospheres, it's so exciting to be a part of a detection like this,” Adams says. “The process of analyzing this data felt magical. We saw hints of this feature in early data, but this higher precision instrument revealed the signature of SO2 clearly and helped us solve the puzzle.”

At an estimated temperature of 1,600 degrees Fahrenheit and an atmosphere made mostly of hydrogen, WASP-39 b is not believed to be habitable. The exoplanet has been compared to both Saturn and Jupiter, with a mass similar to Saturn, but an overall size as big as Jupiter. But the new work points the way to finding evidence of potential life on a habitable planet. 

The planet’s proximity to its host star – eight times closer than Mercury is to our Sun – also makes it a laboratory for studying the effects of radiation from host stars on exoplanets. Better knowledge of the star-planet connection should bring a deeper understanding of how these processes create the diversity of planets observed in the galaxy.

Other atmospheric constituents detected by JWST include sodium, potassium, and water vapor, confirming previous space and ground-based telescope observations as well as finding additional water features, at longer wavelengths, that haven’t been seen before.

JWST also saw carbon dioxide at higher resolution, providing twice as much data as reported from its previous observations. Meanwhile, carbon monoxide was detected, but obvious signatures of both methane and hydrogen sulfide were absent from the data. If present, these molecules occur at very low levels, a significant finding for scientists making inventories of exoplanet chemistry in order to better understand the formation and development of these distant worlds.

Capturing such a broad spectrum of WASP-39 b’s atmosphere was a scientific tour de force, as an international team numbering in the hundreds independently analyzed data from four of JWST’s finely calibrated instrument modes. They then made detailed inter-comparisons of their findings, yielding yet more scientifically nuanced results.

JWST views the universe in infrared light, on the red end of the light spectrum beyond what human eyes can see; that allows the telescope to pick up chemical fingerprints that can’t be detected in visible light.

Each of the three instruments even has some version of the “IR” of infrared in its name: NIRSpec, NIRCam, and NIRISS.

To see light from WASP-39 b, JWST tracked the planet as it passed in front of its star, allowing some of the star’s light to filter through the planet’s atmosphere. Different types of chemicals in the atmosphere absorb different colors of the starlight spectrum, so the colors that are missing tell astronomers which molecules are present.

By so precisely parsing an exoplanet atmosphere, the JWST instruments performed well beyond scientists’ expectations — and promise a new phase of exploration among the broad variety of exoplanets in the galaxy.

López-Morales says, "I am looking forward to seeing what we find in the atmospheres of small, terrestrial planets."

 

###

 

 

About the Center for Astrophysics | Harvard & Smithsonian

 

The Center for Astrophysics | Harvard & Smithsonian is a collaboration between Harvard and the Smithsonian designed to ask—and ultimately answer—humanity’s greatest unresolved questions about the nature of the universe. The Center for Astrophysics is headquartered in Cambridge, MA, with research facilities across the U.S. and around the world.

Large parts of Europe are warming twice as fast as the planet on average

Peer-Reviewed Publication

STOCKHOLM UNIVERSITY

 

IMAGE: LEFT AND RIGHT FIGURES SHOW WARMING IN EUROPE OF THE SUMMER HALF YEAR DURING THE LATEST FOUR DECADES, SUBDIVIDED FOR CLEAR-SKY AND ALL.SKY CONDITIONS, RESPECTIVELY. view more 

CREDIT: PAUL GLANTZ/STOCKHOLM UNIVERSITY

The warming during the summer months in Europe has been much faster than the global average, shows a new study by researchers at Stockholm University published in the Journal of Geophysical Research Atmospheres. As a consequence of human emissions of greenhouse gases, the climate across the continent has also become drier, particularly in southern Europe, leading to worse heat waves and an increased risk of fires.

According to the UN's Intergovernmental Panel on Climate Change (IPCC), warming over land areas occurs significantly faster than over oceans, with 1.6 degrees and 0.9 degrees on average, respectively. It means that the global greenhouse gas emissions budget to stay under a 1.5-degree warming on land has already been used up. Now, the new study shows that the emissions budget to avoid a 2-degree warming over large parts of Europe during the summer half-year (April-September) has also been used up. In fact, measurements reveal that the warming during the summer months in large parts of Europe during the last four decades has already surpassed two degrees.

“Climate change is serious as it leads to, among other things, more frequent heat waves in Europe. These, in turn, increase the risk of fires, such as the devastating fires in southern Europe in the summer of 2022,” says Paul Glantz, Associate Professor at the Department of Environmental Science, Stockholm University, and main author of the study.
 
In southern Europe, a clear, so-called, positive feedback caused by global warming is evident, i.e. warming is amplified due to drier soil and decreased evaporation.  Moreover, there has been less cloud coverage over large parts of Europe, probably as a result of less water vapour in the air.

“What we see in southern Europe is in line what IPCC has predicted, which is that an increased human impact on the greenhouse effect would lead to dry areas on Earth becoming even drier,” says Paul Glantz.

Left and right figures show changes in sensible and latent heat fluxes, respectively, in Europe during the latest four decades of the summer half year

Left and right figures show decrease in clouds in Europe during the latest four decades, for the summer half year, with respect to low level clouds and total amount of clouds throughout the atmosphere, respectively.

CREDIT

Paul Glantz/Stockholm University

Impact of aerosol particles

The study also includes a section about the estimated impact of aerosol particles on the temperature increase. According to Paul Glantz, the rapid warming in, for example, Central and Eastern Europe, is first and foremost a consequence of the human emissions of long-lived greenhouse gases, such as carbon dioxide. But since emissions of short-lived aerosol particles from, for example, coal-fired power plants have decreased greatly over the past four decades, the combined effect has led to an extreme temperature increase of over two degrees.

“The airborne aerosol particles, before they began to decrease in the early 1980s in Europe, have masked the warming caused by human greenhouse gases by just over one degree on average for the summer half-year. As the aerosols in the atmosphere decreased, the temperature increased rapidly. Human emissions of carbon dioxide are still the biggest threat as they affect the climate for hundreds to thousands of years,” says Paul Glantz.

According to Paul Glantz, this effect provides a harbinger of future warming in areas where aerosol emissions are high, such as in India and China.

  

Coal power plants on earth emit over 12 Gt of carbon dioxide each year, nearly one third of the total emissions of carbon dioxide. Coal power plants constitute therefore the single largest source of the global warming. Coal power plants emit also sulphur dioxide that forms aerosols in the atmosphere. Coal power plants have decreased and increased substantially in Europe and East Asia, respectively, during the latest four decades.

CREDIT

Tomasz Matuszewski/Mostphotos

CAPTION

Warming and consequently drier conditions in Europe, particularly for southern countries, higher the risk for fires. In the report “Spreading like wildfires: the rising threat of extraordinary landscape fires”, by UN Environmental Program (UNEP) and GRID-Arendal (a UNEP partner) in 2022, conclude that climate change and land-use change are making wildfires worse. The report anticipates a global increase of extreme fires, even in areas previously unaffected. https://www.unep.org/resources/report/spreading-wildfire-rising-threat-extraordinary-landscape-fires

CREDIT

Ryhor Bruyeu/Mostphotos

Background facts - The greenhouse effect and aerosol effect

Fossil burning leads to the release of both aerosol particles and greenhouse gases. Although their source is common, their effects on climate differ.

About the greenhouse effect
Greenhouse gases are largely unaffected by solar radiation while they absorb infrared radiation efficiently, leading to re-emission towards the Earth's surface. The Earth absorbs both solar radiation and infrared radiation, which leads to the warming of the lower part of the atmosphere in particular.

Time-space: Greenhouse gases are generally long-lived in the atmosphere and this applies above all to carbon dioxide where human emissions affect climate for hundreds to thousands of years. It also means that greenhouse gases spread evenly over the entire planet.

About the aerosol effect
In contrast to greenhouse gases, aerosol particles affect incoming solar radiation, i.e. they scatter part of the sunlight back into space causing a cooling effect. Human emissions of aerosols can enhance this cooling effect.

Time-space: Airborne human aerosol particles have a lifetime of about a week, which means that they mainly cool the climate locally or regionally and in the short term.

According to the Paris Agreement, all parties must commit to drastically reduce their greenhouse gas emissions, but it is also important to decrease concentrations of aerosol particles as well because, in addition to their effects on climate, aerosol particles in polluted air cause approximately eight million premature deaths each year around the world.

---

JOURNAL

Journal of Geophysical Research Atmospheres

DOI

10.1029/2021JD035889 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Unmasking the effects of aerosols on greenhouse warming over Europe

ARTICLE PUBLICATION DATE

22-Nov-2022

Building green energy facilities may produce substantial carbon emissions, says study

But speeding the transition might nearly cancel the effect

Peer-Reviewed Publication

COLUMBIA CLIMATE SCHOOL

 

IMAGE: A NEW STUDY SUGGESTS THAT BUILDING INFRASTRUCTURE FOR CLEANER ENERGY GENERATION WILL BY ITSELF CREATE CARBON EMISSIONS, BUT THE FASTER IT HAPPENS, THE FEWER THEY WILL BE. view more 

CREDIT: ILLUSTRATION BY JULIE MORVANT-MORTREUIL

First, the bad news: Nothing is free. Moving the world energy system away from fossil fuels and into renewable sources will generate carbon emissions by itself, as construction of wind turbines, solar panels and other new infrastructure consumes energy—some of it necessarily coming from the fossil fuels we are trying to get rid of. The good news: If this infrastructure can be put on line quickly, those emissions would dramatically decrease, because far more renewable energy early on will mean far less fossil fuel needed to power the changeover.

This is the conclusion of a study that for the first time estimates the cost of a green transition not in dollars, but in greenhouse gases. The study appears this week in the Proceedings of the National Academy of Sciences.

“The message is that it is going to take energy to rebuild the global energy system, and we need to account for that,” said lead author Corey Lesk, who did the research as a Ph.D. student at the Columbia Climate School’s Lamont-Doherty Earth Observatory. “Any way you do it, it’s not negligible. But the more you can initially bring on renewables, the more you can power the transition with renewables.”

The researchers calculated the possible emissions produced by energy use in mining, manufacturing, transport, construction and other activities needed to create massive farms of solar panels and wind turbines, along with more limited infrastructure for geothermal and other energy sources. Previous research has projected the cost of new energy infrastructure in dollars—$3.5 trillion a year every year until 2050 to reach net-zero emissions, according to one study, or up to about $14 trillion for the United States alone in the same period, according to another. The new study appears to be the first to project the cost in greenhouse gases.

On the current slow pace of renewable infrastructure production (predicted to lead to 2.7 degrees C warming by the end of the century), the researchers estimate these activities will produce 185 billion tons of carbon dioxide by 2100. This alone is equivalent to five or six years of current global emissions—a hefty added burden on the atmosphere. However, if the world builds the same infrastructure fast enough to limit warming to 2 degrees—current international agreement aims to come in under this—those emissions would be halved to 95 billion tons. And, if a truly ambitious path were followed, limiting warming to 1.5 degrees, the cost would be only 20 billion tons by 2100—just six months or so of current global emissions.

The researchers point out that all their estimates are probably quite low. For one, they do not account for materials and construction needed for new electric-transmission lines, nor batteries for storage—both highly energy- and resource-intensive products. Nor do they include the cost of replacing gas- and diesel- powered vehicles with electric ones, or making existing buildings more energy efficient. The study also looks only at carbon-dioxide emissions, which currently cause about 60 percent of ongoing warming—not other greenhouse gases including methane and nitrous oxide.

Other effects of the move to renewables are hard to quantify, but could be substantial. All this new high-tech hardware will require not just massive amounts of base metals including copper, iron and nickel, but previously lesser-used rare elements such as lithium, cobalt, yttrium and neodymium. Many commodities would probably have to come from previously untouched places with fragile environments, including the deep sea, African rain forests and fast-melting Greenland. Solar panels and wind turbines would directly consume large stretches of land, with attendant potential effects on ecosystems and people living there.

“We’re laying out the bottom bound,” said Lesk of the study’s estimates. “The upper bound could be much higher.” But, he says, “the result is encouraging.” Lesk said that given recent price drops for renewable technologies, 80 to 90 percent of what the world needs could be installed in the next few decades, especially if current subsidies for fossil-fuel production are diverted to renewables. “If we get on a more ambitious path, this whole problem goes away. It’s only bad news if we don’t start investing in the next 5 to 10 years.”

As part of the study, Lesk and his colleagues also looked at carbon emissions from adapting to sea-level rise; they found that construction of sea walls and moving cities inland where necessary would generate 1 billion tons of carbon dioxide by 2100 under the 2-degree scenario. This, again, would be only part of the cost of adaptation; they did not look at infrastructure to control inland flooding, irrigation in areas that might become drier, adapting buildings to higher temperatures or other needed projects.

“Despite these limitations, we conclude that the magnitude of CO2 emissions embedded in the broader climate transition are of geophysical and policy relevance,” the authors write. “Transition emissions can be greatly reduced under faster-paced decarbonization, lending new urgency to policy progress on rapid renewable energy deployment.”

The other authors of the study are Denes Csala of the United Kingdom’s University of Lancaster; Robin Krekeler and Antoine Levesque of Germany’s Potsdam Institute for Climate Impacts Research; Sgouris Sgouridis of the Dubai Electricity and Water Authority; Katharine Mach of the University of Miami; Daniel Horen Greenford and H. Damon Matthews of Canada’s Concordia University; and Radley Horton of Lamont-Doherty Earth Observatory. Corey Lesk is now a postdoctoral researcher at Dartmouth College.

Mining for raw materials, transport, manufacturing and construction are all energy-intensive. Here, a mining vehicle at an open-cast mine in Canada’s Northwest Territories.

CREDIT

Kevin Krajick/Earth Institute

Rare commodities newly in demand for green technologies such as lithium, yttrium and neodymium will have to come from new sources. These include fast-melting Greenland (its southeast coast, above), which is rich in these substances.

CREDIT

Margie Turrin/Lamont-Doherty Earth Observatory

Lead author contact:

Corey Lesk  lesk@ldeo.columbia.edu

The Columbia Climate School develops innovative education, supports groundbreaking research and fosters essential solutions, from the community to the planetary scale.  https://climate.columbia.edu/

Lamont-Doherty Earth Observatory develops fundamental knowledge about the origin, evolution and future of the natural world, from the planet’s deepest interior to the outer reaches of its atmosphere, on every continent and in every ocean.
www.ldeo.columbia.edu  |  @LamontEarth

 

---

JOURNAL

Proceedings of the National Academy of Sciences

METHOD OF RESEARCH

Meta-analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Mitigation and Adaptation Emissions Embedded in the Broader Climate Transition

ARTICLE PUBLICATION DATE

21-Nov-2022

IPK researchers identify last remaining steps in the biosynthesis of tropane alkaloids from Coca

Peer-Reviewed Publication

LEIBNIZ INSTITUTE OF PLANT GENETICS AND CROP PLANT RESEARCH

 

IMAGE: PICTURED IS A FLOWER FROM THE COCA PLANT, ERYTHROXYLUM COCA LAM. BENJAMIN CHAVEZ AND COLLEAGUES USED A YEAST BASED SYNTHETIC BIOLOGY PLATFORM TO ELUCIDATE THE LAST REMAINING ENZYMATIC STEPS INVOLVED IN TROPANE ALKALOID FORMATION IN ERYTHROXYLUM COCA. THEIR FINDINGS REVEALED A NEARLY COMPLETE INDEPENDENT ORIGIN HAS EVOLVED WHEN COMPARED TO THE SOLANACEOUS PATHWAY. view more 

CREDIT: DANNY KESSLER

Tropane alkaloids are a particular class of plant derived compounds that have been exploited by mankind since the domestication of medicinal plants. The distribution of these alkaloids is scattered amongst the flowering plants and the two most studied families include those from the Solanaceae (tomato, tobacco, potato relatives) and the Erythroxylaceae (coca). The WHO lists several tropane alkaloids as some of the most important medicines in the modern day pharmacopeia. However other compounds such as cocaine are more infamous for their narcotic and euphorigenic properties. “It is critical to understand how plants produce these alkaloids in order for mankind to continue to build upon nature and develop new useful medicines”, says Dr. John D’ Auria, head of the IPK’s research group “Metabolic Diversity”.

The most studied and characterized system for tropane production has historically been within Solanaceae. There are more than ten chemical modification steps necessary to transform the beginning amino acid precursors into the final active alkaloids and all of these steps were identified and characterized in solanaceous plants. The scattered distribution of tropanes among flowering plants has always hinted that different families may have developed the ability to produce these alkaloids independently from one another. In fact, several steps of tropane biosynthesis were already documented to have evolved independently within members of the Erythroxylaceae.

“We have been working on elucidating the coca derived tropane pathway for the last 15 years and we have been successful in working on several key steps in the biosynthesis of cocaine and other related tropanes in coca”, says the IPK researcher. “The idea that coca would share similar enzymes and genes with their distant solanaceous relatives was incorrect. While the final structure of tropanes is similar, the pathway leading to these alkaloids is different.” 

In order to discover the last remaining steps of the pathway in coca, Dr. John D’ Auria collaborated with the lab of Dr. Christina Smolke from Stanford University. The Smolke group are experts at manipulating yeast and microorganisms to produce important medicinal compounds via synthetic biology methods. “With their assistance, we used the multiplicative power of gene manipulation in yeast to test many different gene candidates for the missing steps in the coca pathway. In essence, at every unknown step, we designed and tested multiple candidate sequences.” These candidate sequences originated from transcriptome studies performed Dr. John D’ Auria’s group as well as the group of Dr. Lyndel Meinhardt from the USDA in Beltsville, Maryland (USA). “Using this powerful gene discovery platform, we successfully identified all the remaining ‘missing steps’ for tropane biosynthesis in coca. This represents the culmination of more than ten graduate student projects in my group and 15 years of my research”, says Dr. John D’ Auria. 

The most significant portions of the findings now confirms that tropane biosynthesis has independently evolved at least twice during the evolution of flowering plants. “This is important because we also show in our study that you can mix and match the Solanaceae and Erythroxylaceae genes and produce tropanes”, says the IPK reseracher. In layman’s terms, the research provides multiple tools for synthetic biologists to begin designing the tropane alkaloid pathway in organisms that have never produced them before, and with the ability to use different enzymes for similar steps, it is possible to optimize or modify those steps for specific chemical outcomes.

“In addition, we also show that the beginning portion of the pathway in coca proceeds by an interesting ‘detour’ or alternate route that doesn’t exist in solanaceous species”, says Benjamin Chavez, the first author of the study and a PhD student in the D’Auria laboratory. “This provides insights in how plant metabolism can find solutions to biochemical challenges. Namely, we can understand the interplay between early precursors and their bottlenecks.”

Lastly, the researchers discovered a specific enzyme that is responsible for the so called ‘carbomethoxy group’ present exclusively in coca alkaloids. Solanaceous species do not have this modification. The carbomethoxy group is partially responsible for the euphorigenic properties of cocaine.

 

---

JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2215372119 

ARTICLE TITLE

Elucidation of tropane alkaloid biosynthesis in Erythroxylum coca using a microbial pathway discovery platform

ARTICLE PUBLICATION DATE

21-Nov-2022

1,700-year-old spider monkey remains discovered in Teotihuacán, Mexico

Researchers found thousands of other items, but the skeletal remains of the monkey point to the earliest evidence of primate captivity, translocation, and gift diplomacy between Teotihuacán and Mayan elite

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - RIVERSIDE

 

IMAGE: COMPLETE SKELETAL REMAINS OF A 1,700 YEAR-OLD FEMALE SPIDER MONKEY FOUND IN TEOTIHUACÁN, MEXICO. view more 

CREDIT: NAWA SUGIYAMA, UC RIVERSIDE.

RIVERSIDE, Calif. -- The complete skeletal remains of a spider monkey — seen as an exotic curiosity in pre-Hispanic Mexico — grants researchers new evidence regarding social-political ties between two ancient powerhouses: Teotihuacán and Maya Indigenous rulers. 

The discovery was made by Nawa Sugiyama, a UC Riverside anthropological archaeologist, and a team of archaeologists and anthropologists who since 2015 have been excavating at Plaza of Columns Complex, in Teotihuacán, Mexico. The remains of other animals were also discovered, as well as thousands of Maya-style mural fragments and over 14,000 ceramic sherds from a grand feast. These pieces are more than 1,700 years old.

The spider monkey is the earliest evidence of primate captivity, translocation, and gift diplomacy between Teotihuacán and the Maya. Details of the discovery will be published in the journal PNAS. This finding allows researchers to piece evidence of high diplomacy interactions and debunks previous beliefs that Maya presence in Teotihuacán was restricted to migrant communities, said Sugiyama, who led the research. 

“Teotihuacán attracted people from all over, it was a place where people came to exchange goods, property, and ideas. It was a place of innovation,” said Sugiyama, who is collaborating with other researchers, including Professor Saburo Sugiyama, co-director of the project and a professor at Arizona State University, and Courtney A. Hofman, a molecular anthropologist with the University of Oklahoma. “Finding the spider monkey has allowed us to discover reassigned connections between Teotihuacán and Maya leaders. The spider monkey brought to life this dynamic space, depicted in the mural art. It’s exciting to reconstruct this live history.”

Researchers applied a multimethod archaeometric (zooarchaeology, isotopes, ancient DNA, paleobotany, and radiocarbon dating) approach to detail the life of this female spider monkey. The animal was likely between 5 and 8 years old at the time of death.

Its skeletal remains were found alongside a golden eagle and several rattlesnakes, surrounded by unique artifacts, such as fine greenstone figurines made of jade from the Motagua Valley in Guatemala, copious shell/snail artifacts, and lavish obsidian goods such as blades and projectiles points. This is consistent with evidence of live sacrifice of symbolically potent animals participating in state rituals observed in Moon and Sun Pyramid dedicatory caches, researchers stated in the paper.

Results from the examination of two teeth, the upper and lower canines, indicate the spider monkey in Teotihuacán ate maize and chili peppers, among other food items. The bone chemistry, which offers insight to the diet and environmental information, indicates at least two years of captivity. Prior to arriving in Teotihuacán, it lived in a humid environment, eating primarily plants and roots.

The research is primarily funded by grants awarded to Sugiyama from the National Science Foundation and National Endowment for the Humanities. Teotihuacán is a pre-Hispanic city recognized as an UNESCO World Heritage site and receives more than three million visitors annually. 

In addition to studying ancient rituals and uncovering pieces of history, the finding allows for a reconstruction of greater narratives, of understanding how these powerful, advanced societies dealt with social and political stressors that very much reflect today’s world, Sugiyama said. 

“This helps us understand principles of diplomacy, to understand how urbanism developed … and how it failed,” Sugiyama said. “Teotihuacán was a successful system for over 500 years, understanding past resilience, its strengths and weaknesses are relevant in today’s society. There are many similarities then and now. Lessons can be seen and modeled from past societies; they provide us with cues as we go forward.” 

The University of California, Riverside is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment is more than 26,000 students. The campus opened a medical school in 2013 and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Center. The campus has an annual impact of more than $2.7 billion on the U.S. economy. To learn more, visit www.ucr.edu.

---

JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2212431119 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animal tissue samples

ARTICLE TITLE

Earliest evidence of primate captivity and translocation supports gift diplomacy between Teotihuacan and the Maya

ARTICLE PUBLICATION DATE

21-Nov-2022

Dust transport in the upper levels of the atmosphere

New study shows that particles from central South America were the main source of iron in the South Pacific during the last two glacial periods

Peer-Reviewed Publication

UNIVERSITY OF OLDENBURG

Dust from the dry Puna Plateau in northwestern Argentina was an important source of iron for the nutrient-deficient South Pacific in the last two glacial cycles – especially at the beginning of these cycles. This was the key finding of a study presented in science journal PNAS by a team of researchers led by geochemist Dr Torben Struve from the University of Oldenburg. According to the team's theory, the jet stream circulation – powerful air currents flowing from west to east at an altitude of several kilometres – picked up the fine mineral particles on the east side of the Andes and transported them almost all the way around the Antarctic continent to the Southeast Pacific. Using a sediment core from the seafloor as a climate archive, the researchers were able to reconstruct the contributions from various dust sources located on the surrounding continents.

Atmospheric dust is a key component of the climate system. On the one hand, fine dust particles influence the Earth's energy budget, because they reflect incoming sunlight at high altitude which has a cooling effect. On the other hand, mineral particles can carry nutrients such as iron and manganese to remote ocean areas where they stimulate the growth of algae. When the algae die and sink to the deep ocean, they remove carbon dioxide from the atmosphere, which also has a cooling effect. These mechanisms can be particularly effective in the remote and iron-deficient subpolar Southern Ocean so that changes in the Southern Hemisphere dust cycle are ascribed a significant role in  the natural alternation between cold glacial and warm interglacial periods in the past. Therefore, the sources and transport pathways of dust have been the subject of intensive research for some time now.

Dust from South America dominated throughout the study period

Struve's team analysed a sediment core from the seafloor of the subpolar South Pacific in which the deposits date all the way back to 260,000 years ago, thus covering two glacial cycles. Using the geochemical fingerprint of the dust fraction in the core, the researchers were able to determine the proportion of particles from South America, South Africa, Australia and New Zealand in the different phases of the two glacial cycles. “We were surprised to find that dust from South America dominated throughout the study period, even though it had to travel a very long distance from the source to our sampling site,” says Struve, lead author of the paper.

According to the analysis, up to two-thirds of the particles originated there, and this proportion was particularly high at the beginning of the glacial cycles. Land masses located closer to the sampling site, such as Australia and New Zealand, contributed only just over half of the deposited dust, and over relatively short periods of time. Their contributions increased particularly towards the end of the glacial periods, when global temperatures started to increase again.

The researchers conclude from this data that the South American dust was emitted from the high elevation source regions of the eastern Andes into the jet stream and travelled around Antarctica in the upper levels of the atmosphere. In contrast, dust particles from the low-elevation source regions in Australia and New Zealand were washed out of the atmosphere more quickly with the rain so they rarely reached such heights for long-distance transport.

The study showed that most of the South American dust came from regions in the Andes spanning the northwest of present-day Argentina and southern Bolivia and located at altitudes of up to 5,000 metres. This area includes parts of the Puna-Altiplano Plateau and the dry high valleys of the Central Andes. Until now, however, it has received little attention from researchers as a potential source of iron for the Southern Ocean. The team reports  that the dust originating from this region contained higher proportions of bioavailable iron during the ice ages, probably due to increased glacial activity in the source regions.

Dust production from all sources increased in the glacial periods

The study concludes that dust production from all sources increased in the glacial periods compared to the warmer interglacial periods, with the result that the iron input from dust increased by a factor of three to six – a finding that confirms earlier studies according to which it was drier and presumably also windier in cooler climates than in warm periods. The team also found evidence in the data that the westerly winds that prevail around Antarctica shifted southwards or slowed down at the end of the ice ages and during the warm interglacial periods.

These findings could contribute to a better understanding of the alternation between glacial and interglacial periods in the Southern Hemisphere, notes Struve: “How exactly natural iron fertilization in the Southern Ocean amplified these climatic changes is not yet fully understood,” the geochemist adds, but he underlines that the new data offers valuable insights and can be incorporated into current Earth system models, which in turn would provide a more detailed picture of the involved processes.

However, the question of whether it makes sense to artificially fertilize nutrient-deficient ocean areas with iron to reduce the current rate of climate change cannot be answered with this study, Struve stresses. “I would be very cautious about that – to achieve a significant effect you would need to supply remote ocean areas with bioavailable iron over long periods of time and on a large scale. That hardly seems feasible.”

In addition to the researchers from the University of Oldenburg’s Institute for Chemistry and Biology of the Marine Environment, a scientist from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research in Bremerhaven and another scientist from the Lamont-Doherty Earth Observatory at Columbia University in New York State participated in the study.  

---

JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2206085119 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Systematic changes to circumpolar dust transport to the Subantarctic Pacific Ocean Over the last two glacial cycles

ARTICLE PUBLICATION DATE

21-Nov-2022